WO2009151070A1 - Method for producing polycrystalline body and apparatus for producing polysilicon - Google Patents

Method for producing polycrystalline body and apparatus for producing polysilicon Download PDF

Info

Publication number
WO2009151070A1
WO2009151070A1 PCT/JP2009/060576 JP2009060576W WO2009151070A1 WO 2009151070 A1 WO2009151070 A1 WO 2009151070A1 JP 2009060576 W JP2009060576 W JP 2009060576W WO 2009151070 A1 WO2009151070 A1 WO 2009151070A1
Authority
WO
WIPO (PCT)
Prior art keywords
group
reaction vessel
silicon
producing
periodic table
Prior art date
Application number
PCT/JP2009/060576
Other languages
French (fr)
Japanese (ja)
Inventor
敏行 渡辺
烈士 中島
陽介 須賀
栄造 渡辺
Original Assignee
株式会社シリコンプラス
国立大学法人東京農工大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社シリコンプラス, 国立大学法人東京農工大学 filed Critical 株式会社シリコンプラス
Publication of WO2009151070A1 publication Critical patent/WO2009151070A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02521—Materials
    • H01L21/02524—Group 14 semiconducting materials
    • H01L21/02532—Silicon, silicon germanium, germanium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J19/087—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J19/088—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
    • B01J3/008—Processes carried out under supercritical conditions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02587—Structure
    • H01L21/0259—Microstructure
    • H01L21/02595—Microstructure polycrystalline
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02612—Formation types
    • H01L21/02617—Deposition types
    • H01L21/0262—Reduction or decomposition of gaseous compounds, e.g. CVD
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0803—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J2219/0805—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B01J2219/0807—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes
    • B01J2219/0809—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes employing two or more electrodes
    • B01J2219/0811—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes employing two or more electrodes employing three electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0803—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J2219/0805—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B01J2219/0807—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes
    • B01J2219/0837—Details relating to the material of the electrodes
    • B01J2219/0839—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0869—Feeding or evacuating the reactor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0871—Heating or cooling of the reactor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0875—Gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0894—Processes carried out in the presence of a plasma
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids

Definitions

  • the present invention relates to a method for producing a polycrystalline body and an apparatus for producing polysilicon.
  • Patent Document 1 describes a method of forming a DLC film in which a diamond-like carbon film (DLC film) is formed on a base material by a plasma CVD method (Chemical Vapor Deposition).
  • Patent Document 2 describes a semiconductor device having a polysilicon film formed by a CVD method.
  • Patent Document 3 describes a polycrystalline silicon rod manufactured by the Siemens method.
  • Patent Document 4 describes a method for producing acicular crystalline silicon by a gas phase synthesis reaction of silicon tetrachloride and zinc (Zn).
  • Patent Document 5 describes a method for producing high-purity silicon in which a gas phase reaction between silicon tetrachloride and zinc metal is performed in zinc chloride gas.
  • the diamond-like carbon film is widely used in applications such as an LSI interlayer insulating film utilizing an insulating property and a low dielectric constant.
  • the application of polysilicon is expanding in fields such as solar cells and electronic materials. For this reason, a production method capable of high-speed synthesis of these materials is desired.
  • the conventional CVD method is usually performed under a reduced pressure of several tens to several hundreds of pascals, there are problems that the concentration of the source gas is extremely low and the crystal growth rate is slow.
  • the Siemens method which is known as a method for manufacturing polysilicon, has problems that it consumes excessive power and the growth rate is slow.
  • the objective of this invention is providing the manufacturing method etc. which obtain the polycrystal of a periodic table 14 group element at high speed.
  • the invention according to claim 1 is a method for producing a polycrystal, wherein a halide of a group 14 element of a periodic table is introduced into a reaction vessel equipped with an electrode, and a halide of a group 14 element of the periodic table is introduced.
  • a carrier gas is introduced into the reaction vessel in advance, and then a halide of a group 14 element of the periodic table is introduced into the reaction vessel.
  • the invention according to claim 3 is characterized in that the supercritical formation step introduces 0.1 to 100,000 ml of a halide of a group 14 element of the periodic table with respect to 50 ml of a carrier gas in the reaction vessel.
  • the invention according to claim 4 is characterized in that the supercritical formation step uses at least one selected from the group consisting of argon, helium, neon and xenon as a carrier gas. It is a manufacturing method of a body.
  • the invention according to claim 5 is the method for producing a polycrystalline body according to claim 1, wherein the group 14 element of the periodic table is selected from silicon (Si) and germanium (Ge).
  • the invention according to claim 6 is the method for producing a polycrystal according to claim 1, wherein the halide of the group 14 element of the periodic table is chloride or bromide.
  • the invention according to claim 7 is the method for producing a polycrystalline body according to claim 1, wherein the halide of the group 14 element of the periodic table is silicon tetrachloride.
  • the invention according to claim 8 is characterized in that the pressure in the reaction vessel is maintained at 3 MPa or higher and the temperature in the reaction vessel is maintained at 80 K or higher. Is the method.
  • the invention according to claim 9 is characterized in that in the plasma discharge step, a polycrystalline body of a group 14 element of the periodic table is precipitated on a seed crystal. It is.
  • the invention according to claim 10 is the method for producing a polycrystalline body according to claim 9, wherein the temperature of the seed crystal is maintained at 450K or higher.
  • the polycrystalline member of the periodic table group 14 element is maintained at a temperature higher than the melting point of the polycrystalline member of the periodic table group 14 element.
  • the method for producing a polycrystalline body according to claim 1 wherein the polycrystalline body of the group 14 element of the periodic table is precipitated and melted.
  • the invention according to claim 12 is the method for producing a polycrystalline body according to claim 11, wherein the temperature of the precipitation member is maintained at 1800 K or more.
  • the invention according to claim 13 is the method for producing a polycrystal according to claim 1, wherein the polycrystal of the group 14 element of the periodic table is polysilicon.
  • the invention according to claim 14 is an apparatus for producing polysilicon, wherein a reaction vessel body for forming a supercritical fluid state of a silicon halide compound introduced therein, and the inside of the reaction vessel body An electrode for performing plasma discharge, and silicon decomposed by the plasma discharge provided inside the reaction vessel main body and deposited on a surface maintained at a temperature higher than the melting point of the silicon, and deposited
  • a polysilicon manufacturing apparatus comprising: a deposition member that melts the silicon; and a recovery member that collects the silicon melted on the deposition member.
  • the deposition member has a funnel-like shape, and the main body portion includes a conical main body portion and the silicon deposited and melted on the surface of the main body portion.
  • the invention according to claim 16 is the polysilicon manufacturing apparatus according to claim 14, wherein the deposition member is made of graphite.
  • a polycrystal of a periodic table group 14 element can be obtained at high speed.
  • polysilicon has high crystallinity similar to that of single crystal silicon.
  • FIG. 1 is a diagram for explaining an example of a production apparatus for carrying out a method for producing a polycrystalline body to which the present embodiment is applied.
  • the manufacturing apparatus I includes a reaction vessel 110 having a pressure resistance capable of maintaining a supercritical fluid state of a halide of a periodic table 14 group element, which will be described later, and a super vessel formed in the reaction vessel 110.
  • a high frequency power source 27 that supplies power for plasma discharge is connected to the electrodes 111 and 121 via a matching unit 26.
  • the halide of the group 14 element of the periodic table stored in the raw material storage tank 21 opens the raw material supply valve 21a, the temperature is adjusted by the thermostatic device 23, and the predetermined supply device 24 supplies the raw material supply pipe 21L.
  • the carrier gas stored in the carrier gas storage tank 22 is supplied to the reaction vessel 110 through the gas supply pipe 22L by opening the pressure adjustment valve 22a.
  • the pressure in the reaction vessel 110 is adjusted by the exhaust pressure adjusting valve 25 through the exhaust pressure pipe 10L.
  • a substrate 30 for laminating a polycrystal of a group 14 element of the periodic table in the vicinity of the electrodes 111 and 121 in the reaction vessel 110 and a heater for maintaining the substrate 30 at a predetermined temperature. 31 is provided.
  • a heating device for heating the reaction vessel 110 to a predetermined temperature is provided. Examples of the heating device include a jacket type heater and a cartridge type heater using a predetermined heat medium. Moreover, you may install the reaction container 110 in a thermostat.
  • the material constituting the electrodes 111 and 121 is not particularly limited as long as it is a material capable of plasma discharge.
  • the material constituting the pure metal electrode includes manganese, iron, cobalt, nickel, copper, zinc, silver, tin, aluminum, tungsten, platinum, gold, and the like.
  • the material constituting the electrode to be plated include silver-plated iron, galvanized iron, and tin-plated iron.
  • the material constituting the alloy electrode include brass, iron nickel alloy, iron cobalt alloy, and magnesium alloy. Among these, manganese, copper, zinc, platinum, gold, galvanized iron, and brass are preferable.
  • the distance between the electrodes 111 and 121 is selected according to the temperature, pressure or discharge conditions in the reaction vessel 110 and is not particularly limited. In the present embodiment, the distance between the electrodes is set within a range of 0.002 mm to 5 mm. In the present embodiment, the tip portions of the electrodes 111 and 121 are removable. The tip portions of the electrodes 111 and 121 are made of, for example, carbon steel.
  • the material constituting the reaction vessel 110 is not particularly limited as long as the material can maintain the supercritical fluid state of the halide of the group 14 element of the periodic table.
  • stainless steel can be used.
  • Hastelloy C registered trademark
  • the material composing the substrate 30 is not particularly limited as long as it is possible to stack a polycrystal of the group 14 element of the periodic table, and in this embodiment, a SUS substrate is used.
  • the substrate 30 is heated by a heater 31 and is usually maintained at a temperature of about 400 ° C. to 500 ° C.
  • the carrier gas is preferably inert to the halide of the Group 14 element used as a raw material, and examples thereof include helium, neon, and argon. In this embodiment, argon is used as the carrier gas.
  • halides of group 14 elements of the periodic table used as raw materials in the present embodiment will be described.
  • the halide of the group 14 element in the periodic table used in this embodiment include a halogenated carbon compound, a halogenated silicon compound, and a halogenated germanium compound.
  • a halogenated silicon compound and a halogenated germanium compound are preferable, and a silicon halide compound is particularly preferable.
  • silicon halide compound examples include silicon fluoride, silicon chloride, silicon bromide, and silicon iodide. Among these, silicon chloride and silicon bromide are preferable.
  • silicon chloride examples include tetrachlorosilane (SiCl 4 ), hexachlorodisilane, octachlorotrisilane, decachlorotrisilane, dodecachloropentasilane, and the like.
  • silane derivatives such as chlorosilane (SiH 3 Cl), dichlorosilane (SiH 2 Cl 2 ), and trichlorosilane (SiHCl 3 ) can be given.
  • silicon bromide examples include silicon tetrabromide (SiBr 4 ), disilicon hexabromide, trisilicon octabromide, tetrasilicon decabromide and the like. Furthermore, silicon bromide trichloride, silicon dibromide dichloride, silicon tribromide chloride, silicon iodide trichloride, silicon chlorosulfide, hexachlorodisiloxane and the like can be mentioned. Among these, tetrachlorosilane (SiCl 4 ) is particularly preferable.
  • Halogenated germanium compound examples include germanium fluoride, germanium chloride, germanium bromide, and germanium iodide. Among these, germanium chloride and germanium bromide are preferable. Examples of germanium chloride include germanium dichloride and germanium tetrachloride. Examples of germanium bromide include germanium dibromide and germanium tetrabromide.
  • a solution in which the raw material is dissolved in a predetermined solvent is prepared in advance, and this solution is supplied to the reaction vessel 110.
  • the solvent that can be used is not particularly limited as long as it can dissolve a halide of a group 14 element of the periodic table.
  • the material is selected from known materials in consideration of the critical temperature and critical pressure inherent to the solvent in the supercritical fluid state described later. Specific examples include carbon dioxide, trifluoromethane (fluoroform), ethane, propane, butane, benzene, methyl ether, chloroform and the like.
  • the pressure regulating valve 22a is opened, and argon stored in the carrier gas storage tank 22 is supplied to the reaction vessel 110 through the gas supply pipe 22L.
  • the raw material supply valve 21a is opened, and tetrachlorosilane stored in the raw material storage tank 21 is supplied to the reaction vessel 110 by the supply device 24 via the raw material supply pipe 21L.
  • a liquid feed pump is used as the feeder 24.
  • Tetrachlorosilane is adjusted to a predetermined temperature by the thermostat 23 before being supplied to the reaction vessel 110. Thereby, it can pressurize rapidly to the target pressure and can stabilize a pressure.
  • the temperature of the tetrachlorosilane whose temperature is adjusted by the thermostat 23 is not particularly limited, but in the present embodiment, it is usually in the range of 25 to 300 ° C., preferably 60 to 250 ° C.
  • the ratio of tetrachlorosilane and argon supplied to the reaction vessel 110 is not particularly limited.
  • the amount of tetrachlorosilane is 0.1 ml to 100,000 ml, preferably 10 ml to 5,000 ml, more preferably 10 ml to 200 ml with respect to 50 ml of argon.
  • the ratio of tetrachlorosilane to argon is excessively small, the production rate of polysilicon tends to be slow. If the ratio of tetrachlorosilane to argon is excessively large, the plasma discharge tends to become unstable.
  • the pressure in the reaction vessel 110 to which tetrachlorosilane and argon are supplied is adjusted using the pressure regulating valve 22a and the exhaust pressure regulating valve 25.
  • the pressure in the reaction vessel 110 is not particularly limited, but in the present embodiment, it is usually adjusted in the range of 3 MPa to 20 MPa, preferably 5 MPa to 10 MPa.
  • the reaction vessel 110 is heated using a predetermined heater (not shown) to form a supercritical fluid state of a mixture of tetrachlorosilane and argon supplied to the reaction vessel 110.
  • the supercritical fluid state is defined as a non-condensable fluid that exceeds the gas-liquid critical temperature inherent to the substance. That is, when gas and liquid are present in the sealed container, the liquid thermally expands as the temperature rises, and its density decreases. On the other hand, the density of gas increases as the vapor pressure increases. And finally, the density of both becomes equal, and it becomes a uniform state indistinguishable from gas and liquid.
  • the critical point In the temperature-pressure diagram (not shown) of the substance, the point where such a state is reached is called the critical point, the critical point temperature is called the critical temperature (Tc), and the critical point pressure is called the critical pressure (Pc).
  • Tc critical temperature
  • Pc critical pressure
  • a supercritical fluid state means that the temperature and pressure of a substance exceed a critical point.
  • the tetrachlorosilane has a critical temperature (Tc) of 233.6 ° C. (506.75 K) and a critical pressure (Pc) of 3.73 MPa.
  • the critical temperature (Tc) of argon is -185.7 ° C. (87.45 K), and the critical pressure (Pc) is 4.86 MPa.
  • the critical temperature (Tc) and critical pressure (Pc) of the mixture depend on the composition of tetrachlorosilane and argon, and the critical temperature (Tc) and critical pressure (Pc) of each substance. ) Can be adjusted between.
  • the temperature of the reaction vessel 110 is usually heated to be in the range of 300K to 600K, preferably 313K to 510K. Further, the pressure in the reaction vessel 110 is usually maintained in the range of 4.86 MPa to 40 MPa, preferably 4 MPa to 10 MPa. Under such conditions, a supercritical fluid state of a mixture of tetrachlorosilane and argon is formed in the reaction vessel 110.
  • the discharge conditions for generating plasma discharge are not particularly limited and are selected depending on the distance between the electrodes 111 and 121 and the pressure in the reaction vessel 110.
  • the plasma discharge time is suitably set to about several seconds to several hours.
  • the tetrachlorosilane is decomposed and reacted, and the reaction vessel 110.
  • Polycrystalline silicon is formed on the surface of the substrate 30 provided inside, the surfaces of the electrodes 111 and 121, and the inner wall surface of the reaction vessel 110.
  • the high-frequency power source 27 when performing plasma discharge has been described, but a DC power source may be used instead.
  • polycrystalline silicon is generated on both electrodes and the like.
  • a DC power source when a DC power source is used, a large amount of polycrystalline silicon is efficiently formed on one electrode (cathode) or on a predetermined substrate provided near one electrode. Crystalline silicon is produced.
  • FIG. 7 is a diagram for explaining the second embodiment.
  • the same reference numerals are used for the same components as those of the manufacturing apparatus I described in the first embodiment (FIG. 1), and the description thereof is omitted.
  • the manufacturing apparatus II shown in FIG. 7 includes a reaction vessel (reaction vessel body) 120 having a pressure resistance capable of maintaining a supercritical fluid state of a halide of a group 14 element of the periodic table, and a super vessel formed in the reaction vessel 120.
  • a high frequency power supply 27 that supplies power for plasma discharge is connected to the electrodes 112 and 122 via a matching unit 26.
  • the halide of the group 14 element of the periodic table stored in the raw material storage tank 21 opens the raw material supply valve 21a, the temperature is adjusted by the thermostatic device 23, and the predetermined supply device 24 supplies the raw material supply pipe 21L.
  • the carrier gas stored in the carrier gas storage tank 22 is supplied to the reaction vessel 120 through the gas supply pipe 22L by opening the pressure adjustment valve 22a.
  • the pressure in the reaction vessel 120 is adjusted by the exhaust pressure adjustment valve 25.
  • a seed crystal 40 is provided in the vicinity of the electrodes 112 and 122 in the reaction vessel 120 for precipitating a polycrystal of a group 14 element of the periodic table.
  • an external power source 42 for applying a predetermined voltage to the carbon electrodes 41 attached to both ends of the seed crystal 40 is provided.
  • the seed crystal 40 is attached so that both ends are fixed to the bottom of the reaction vessel 120 and the intermediate portion formed in an inverted U shape faces the electrodes 112 and 122 side. It has been. Carbon electrodes 41 are joined to both ends of the seed crystal 40, and these are electrically joined to an external power source 42 provided outside the reaction vessel 120.
  • the material constituting the seed crystal 40 is preferably a single crystal of a group 14 element of the periodic table to be precipitated, and examples thereof include a silicon single crystal and a germanium single crystal. Further, silicon carbide (SiC) or the like can be used.
  • the radical of the group 14 element of the periodic table that has reached the surface of the seed crystal 40 is induced to be crystallized by the seed crystal 40, and solid-phase epitaxial growth occurs, so that a polycrystalline body is finally obtained. .
  • the size of the seed crystal 40 on which the periodic table group 14 element is deposited is not particularly limited, but in the present embodiment, a square column of about 5 mm in one piece is bent into an inverted U shape and formed to have a height of about 20 mm. ing.
  • As seed crystals crystal grains having a particle size of about several nm to several hundreds nm can be used.
  • the material which comprises the carbon electrode 41 attached to the both ends of the seed crystal 40 is not specifically limited. In the present embodiment, a carbon electrode material is used.
  • the seed crystal 40 is usually 450 K (473 ° C.) or higher, preferably 500 K (273 ° C.) or higher, by applying a voltage to the carbon electrodes 41 attached to both ends of the seed crystal 40 using an external power source 42. Is kept at a temperature of However, for example, when the group 14 element of the periodic table is silicon (Si), the temperature is kept at a temperature lower than the melting point of 1,687 K (1,414 ° C.) of polysilicon.
  • FIG. 8 is a diagram for explaining the third embodiment.
  • the same reference numerals are used for the same components as those of the manufacturing apparatus I described in the first embodiment (FIG. 1), and the description thereof is omitted.
  • the manufacturing apparatus III includes a reaction vessel (reaction vessel body) 130 having a pressure resistance capable of maintaining a supercritical fluid state of silicon tetrachloride, which is one of silicon halide compounds, and a reaction vessel.
  • a deposition member 50 for depositing and melting polysilicon is provided in the vicinity of the electrodes 113 and 123 in the reaction vessel 130.
  • the deposition member 50 is held by the holder 51 in the vicinity of the electrodes 113 and 123 in the reaction vessel 130.
  • Precipitation member 50 is heated to a temperature higher than the melting point of polysilicon by a predetermined heating device (not shown).
  • the deposition member 50 is heated to about 1,700 K (1,427 ° C.) to about 2000 K (1,727 ° C.).
  • a crucible (recovery member) 52 is provided that recovers polysilicon that has precipitated and melted on the surface of the deposition member 50 and has flowed down to the deposition member 50.
  • the material constituting the deposition member 50 is not particularly limited as long as it can be maintained at a temperature higher than the melting point of polysilicon.
  • high purity graphite is used.
  • the material which comprises the crucible 52 is not specifically limited, For example, quartz, a graphite, a Hastelloy alloy etc. are mentioned. Further, it is preferable to attach a silicon plate or the like on the wall surface of the crucible 52 to prevent contamination.
  • graphite or quartz is used as the material constituting the crucible 52.
  • FIG. 9 is a diagram illustrating the deposition member 50.
  • the deposition member 50 has a funnel-like shape composed of a conical body portion 50a and a tubular portion 50b.
  • a plurality of heating wires 50 c made of silicon carbide (SiC) are embedded in the deposition member 50.
  • the deposition member 50 is energized to a plurality of heating wires 50c using a predetermined power source (not shown), so that the temperature is higher than the melting point of polysilicon (about 1,687 K (1,414 ° C.)) (usually normal). , About 1,800 K (1,527 ° C. or higher).
  • the polysilicon deposited on the surface of the deposition member 50 flows downward through the main body portion 50a and the tubular portion 50b in a liquid state.
  • silicon tetrachloride is decomposed and reacted by applying power between the electrodes 113 and 123 in a supercritical fluid state of a mixture of silicon tetrachloride and argon to generate plasma discharge. And deposited on the surface of the deposition member 50 provided in the reaction vessel 130. As described above, the deposition member 50 is energized through a plurality of heating wires 50c embedded therein, so that the deposition member 50 has a temperature higher than the melting point of polysilicon (approximately 1,687 K (1,414 ° C.)) of approximately 1,800 K. The above temperature is maintained.
  • the polysilicon deposited on the surface of the deposition member 50 flows down through the conical body portion 50a and the tubular portion 50b above the deposition member 50 in a liquid state. Subsequently, the polysilicon that has flowed down to the deposition member 50 is cooled in the middle of the flow, and the cooled polysilicon is usually precipitated in the form of particles having a diameter of about 0.5 mm to 1 mm in this embodiment. It is collected in a crucible 52 provided below the member 50 for use.
  • polycrystalline silicon (polysilicon) is manufactured by the following operation.
  • a pressure-resistant cell (internal capacity: 50 ml) made of Hastelloy C that can be energized is used.
  • a liquid feeding pump (manufactured by JASCO Corporation) as the feeder 24, a fully automatic pressure adjusting valve (manufactured by JASCO Corporation) as the gas pressure adjusting valve 22a, and a fully automatic exhaust pressure adjusting valve (JASCO Corporation) as the exhaust pressure adjusting valve 25 Company).
  • the electrodes 111 and 121 parallel plate electrodes having a size of 10 mm ⁇ 20 mm are attached to the reaction vessel 110.
  • the electrodes 111 and 121 As materials for the electrodes 111 and 121, brass, galvanized iron, and SUS are used. The distance between the electrodes 111 and 121 is set to 0.01 mm.
  • the high-frequency power source 27 an AC generator (PSG-1301 manufactured by Tokyo High Power Co., Ltd.), a high frequency generator (PA-150 manufactured by Tokyo High Power Co., Ltd.) and a DC converter (PS-330 manufactured by Tokyo High Power Co., Ltd.) are used.
  • the matching unit 26 As the matching unit 26, HC-2000 manufactured by Tokyo High Power Co., Ltd. is used.
  • the raw material storage tank 21 is filled with silicon tetrachloride having a purity of 99.9%.
  • the carrier gas storage tank 22 is filled with argon gas having a purity of 99.9%.
  • argon gas is supplied from the carrier gas storage tank 22 into the reaction container 110, and then silicon tetrachloride is supplied from the raw material storage tank 21 into the reaction container 110.
  • the pressure in the reaction vessel 110 is increased to 5 MPa, the temperature is raised to 308 K, a supercritical fluid state of a mixture of silicon tetrachloride and argon gas is formed, and the mixture is left for about 20 minutes.
  • 100 W of electric power is applied to the electrodes 111 and 121 by the high frequency power supply 27 (13.56 MHz) for about 3 minutes to generate plasma discharge.
  • reaction vessel 110 is cooled, and the pressure in the reaction vessel 110 is reduced at a rate of 0.1 MPa / min.
  • polycrystalline silicon is formed on the surface of the substrate 30 provided in the reaction vessel 110, the surfaces of the electrodes 111 and 121, and the inner wall surface of the reaction vessel 110.
  • Polycrystalline silicon is formed in either case when brass, galvanized iron, or SUS is used as the material of the electrodes 111 and 121.
  • FIG. 2 shows a plasma emission spectrum in a supercritical fluid state of a mixture of silicon tetrachloride and argon gas.
  • peaks corresponding to silicon atoms 212.1 nm, 221.3 nm, 251.9 nm, and 288.4 nm are observed.
  • very strong peaks are detected at 221.3 nm and 251.9 nm.
  • FIG. 3 is an SEM image of spherical polycrystalline silicon formed on the surfaces of the electrodes 111 and 121. As shown in FIG. 3A, it can be seen that spherical polycrystalline silicon having a diameter of several hundred nm to 5 ⁇ m is formed on the surfaces of the electrodes 111 and 121. In addition, a horizontal bar shows 25 micrometers in length. FIG. 3B is an enlarged image of one of the spherical polycrystalline silicons shown in FIG. The horizontal bar shown in the lower part of FIG. 3B has a length of 3.5 ⁇ m. Silicon is detected in the spherical portion by the elemental analysis chart and elemental mapping. The SEM image of the spherical polycrystalline silicon was observed with a scanning electron microscope (SEM: FE-SEM S-4500 manufactured by Hitachi, Ltd.).
  • SEM scanning electron microscope
  • FIG. 4 shows an EDX (Energy Dispersive X-ray Fluorescence Spectrometer) mapping image (FIG. 4A) and EDX of spherical polycrystalline silicon formed on the surfaces of the electrodes 111 and 121. It is a chart (FIG.4 (b)).
  • the EDX mapping image has an analysis depth of 1 ⁇ m to 2 ⁇ m, and it can be seen that the spherical portion is polycrystalline silicon.
  • the EDX chart of FIG.4 (b) has shown that the polycrystal silicon produced
  • FIG. 5 is an SEM image of film-like polycrystalline silicon formed in the vicinity of the spherical portion shown in FIG. As shown in FIG. 5A, many cracks are observed in the polycrystalline silicon film formed on the surfaces of the electrodes 111 and 121.
  • the horizontal bar indicates a length of 90 ⁇ m.
  • FIG. 5B is an enlarged image of the SEM image of FIG. The horizontal bar indicates a length of 15 ⁇ m. As shown in FIG. 5B, a slightly fine pattern is observed on the surface of the polycrystalline silicon film.
  • FIG. 5C is a further enlarged SEM image. The horizontal bar indicates a length of 1.5 ⁇ m. As shown in FIG. 5C, a fine pattern is clearly observed on the surface of the polycrystalline silicon film, and it can be seen that dense polycrystalline silicon is formed.
  • FIG. 6 shows a Raman spectrum of polycrystalline silicon (CSCFD) formed on the surfaces of the electrodes 111 and 121 (solid line).
  • the Raman spectrum is measured using a laser Raman spectrophotometer (NRS-1000 manufactured by JASCO Corporation). The wavelength of the excitation light is 647 nm, and the resolution is 0.54 cm ⁇ 1 .
  • a Raman spectrum (dotted line) of a silicon single crystal plate (Si Wafer) is also shown.
  • the Raman spectrum of the spherical portion formed on the surfaces of the electrodes 111 and 121 has a wave number (Wavenumber / cm ⁇ 1) similar to the Raman spectrum of the silicon single crystal. ), A similar sharp peak is observed.
  • reaction vessel 110, 120, 130 ... reaction vessel, 111, 121, 112, 122, 113, 123, ... electrode, 21 ... raw material storage tank, 22 ... carrier gas storage tank, 27 ... high frequency power supply, 30 ... substrate, 40 ... seed crystal, 50 ... Precipitation member, 52 ... Crucible, I, II, III ... Production equipment

Abstract

Disclosed is a method for producing a polycrystalline body, which comprises: a supercritical state-forming step wherein a halide of a group 14 element of the periodic table is introduced into a reaction chamber (110) which is provided with electrodes (111, 121), thereby forming a supercritical fluid state of the halide of a group 14 element of the periodic table; and a plasma discharge step wherein power is applied between the electrodes (111, 121) in the thus-formed supercritical fluid state, thereby generating a plasma discharge and producing a polycrystalline body of the group 14 element of the periodic table.  Consequently, a polycrystalline body of the group 14 element of the periodic table can be obtained at a high rate.

Description

多結晶体の製造方法及びポリシリコンの製造装置Polycrystalline manufacturing method and polysilicon manufacturing apparatus
　本発明は、多結晶体の製造方法及びポリシリコンの製造装置に関する。 The present invention relates to a method for producing a polycrystalline body and an apparatus for producing polysilicon.
　従来、炭素（Ｃ）やケイ素（Ｓｉ）等の周期表１４族元素の多結晶体を得る方法が知られている。例えば、特許文献１には、プラズマＣＶＤ法（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｕｒ　Ｄｅｐｏｓｉｔｉｏｎ：化学気相成長法）によるダイヤモンドライクカーボン膜（ＤＬＣ膜）を基材に形成するＤＬＣ膜の成膜法が記載されている。また、特許文献２には、ＣＶＤ法により形成されたポリシリコン膜を有する半導体装置が記載されている。さらに、特許文献３には、シーメンス法により製造された多結晶シリコンロッドが記載されている。 Conventionally, a method for obtaining a polycrystal of a group 14 element of the periodic table such as carbon (C) or silicon (Si) is known. For example, Patent Document 1 describes a method of forming a DLC film in which a diamond-like carbon film (DLC film) is formed on a base material by a plasma CVD method (Chemical Vapor Deposition). Patent Document 2 describes a semiconductor device having a polysilicon film formed by a CVD method. Furthermore, Patent Document 3 describes a polycrystalline silicon rod manufactured by the Siemens method.
　また、最近では、四塩化ケイ素（ＳｉＣｌ４）の還元方法が見直されている。例えば、特許文献４には、四塩化ケイ素と亜鉛（Ｚｎ）の気相合成反応による針状結晶性シリコンの製造方法が記載されている。さらに、特許文献５には、塩化亜鉛ガス中で四塩化ケイ素と金属亜鉛との気相反応を行う高純度シリコンの製造方法が記載されている。 Recently, a method for reducing silicon tetrachloride (SiCl 4 ) has been reviewed. For example, Patent Document 4 describes a method for producing acicular crystalline silicon by a gas phase synthesis reaction of silicon tetrachloride and zinc (Zn). Further, Patent Document 5 describes a method for producing high-purity silicon in which a gas phase reaction between silicon tetrachloride and zinc metal is performed in zinc chloride gas.
特開平０８－２１７５９６号公報Japanese Patent Application Laid-Open No. 08-217596 特開平０７－１８３５２９号公報Japanese Patent Application Laid-Open No. 07-183529 特開２００４－２７７２２３号公報JP 2004-277223 A 特開２００６－２９０６４５号公報JP 2006-290645 A 特開２００４－２１０５９４号公報Japanese Patent Laid-Open No. 2004-210594
　ところで、ダイヤモンドライクカーボン膜は、絶縁性や低誘電率を利用したＬＳＩ層間絶縁膜等の適用分野が広がっている。また、ポリシリコンは、太陽電池や電子材料等の分野の応用が拡大している。このため、これらの材料の高速合成が可能な製造方法は望まれている。
　しかし、従来のＣＶＤ法は、通常、数十～数百パスカルの減圧下で行われるため、原料ガスの濃度が極めて低く、結晶成長速度が遅いという問題がある。また、ポリシリコンの製造方法として知られているシーメンス法は、過大な電力を消費し、成長速度も遅いという問題がある。
　本発明の目的は、周期表１４族元素の多結晶体を高速で得る製造方法等を提供することにある。 By the way, the diamond-like carbon film is widely used in applications such as an LSI interlayer insulating film utilizing an insulating property and a low dielectric constant. Further, the application of polysilicon is expanding in fields such as solar cells and electronic materials. For this reason, a production method capable of high-speed synthesis of these materials is desired.
However, since the conventional CVD method is usually performed under a reduced pressure of several tens to several hundreds of pascals, there are problems that the concentration of the source gas is extremely low and the crystal growth rate is slow. In addition, the Siemens method, which is known as a method for manufacturing polysilicon, has problems that it consumes excessive power and the growth rate is slow.
The objective of this invention is providing the manufacturing method etc. which obtain the polycrystal of a periodic table 14 group element at high speed.
　本発明によれば、下記請求項１乃至１６に係る多結晶体の製造方法、ポリシリコンの製造装置が提供される。
（１）請求項１に係る発明は、多結晶体の製造方法であって、電極を備えた反応容器中に周期表１４族元素のハロゲン化物を導入し、周期表１４族元素のハロゲン化物の超臨界流体状態を形成する超臨界形成工程と、形成された前記超臨界流体状態にて、前記電極間に電力を印加することによりプラズマ放電を発生させ、周期表１４族元素の多結晶体を生成させるプラズマ放電工程と、を有することを特徴とする多結晶体の製造方法である。
（２）請求項２に係る発明は、前記超臨界形成工程は、予め前記反応容器中にキャリアガスを導入し、その後、周期表１４族元素のハロゲン化物を当該反応容器中に導入することを特徴とする請求項１に記載の多結晶体の製造方法である。
（３）請求項３に係る発明は、前記超臨界形成工程は、前記反応容器中にキャリアガス５０ｍｌに対し、周期表１４族元素のハロゲン化物０．１～１００，０００ｍｌを導入することを特徴とする請求項１に記載の多結晶体の製造方法である。
（４）請求項４に係る発明は、前記超臨界形成工程は、キャリアガスとしてアルゴン、ヘリウム、ネオン、キセノンから選ばれる少なくとも１種を使用することを特徴とする請求項１に記載の多結晶体の製造方法である。
（５）請求項５に係る発明は、周期表１４族元素が、珪素（Ｓｉ）及びゲルマニウム（Ｇｅ）から選ばれることを特徴とする請求項１に記載の多結晶体の製造方法である。
（６）請求項６に係る発明は、周期表１４族元素のハロゲン化物が、塩化物又は臭化物であることを特徴とする請求項１に記載の多結晶体の製造方法である。
（７）請求項７に係る発明は、周期表１４族元素のハロゲン化物が、四塩化ケイ素であることを特徴とする請求項１に記載の多結晶体の製造方法である。 According to the present invention, a polycrystalline body manufacturing method and a polysilicon manufacturing apparatus according to the following claims 1 to 16 are provided.
(1) The invention according to claim 1 is a method for producing a polycrystal, wherein a halide of a group 14 element of a periodic table is introduced into a reaction vessel equipped with an electrode, and a halide of a group 14 element of the periodic table is introduced. A supercritical forming step for forming a supercritical fluid state, and in the formed supercritical fluid state, a plasma discharge is generated by applying electric power between the electrodes, and a polycrystal of a group 14 element of the periodic table is formed. And a plasma discharge step to be generated.
(2) In the invention according to claim 2, in the supercritical forming step, a carrier gas is introduced into the reaction vessel in advance, and then a halide of a group 14 element of the periodic table is introduced into the reaction vessel. The method for producing a polycrystalline body according to claim 1, wherein the method is characterized in that:
(3) The invention according to claim 3 is characterized in that the supercritical formation step introduces 0.1 to 100,000 ml of a halide of a group 14 element of the periodic table with respect to 50 ml of a carrier gas in the reaction vessel. The method for producing a polycrystalline body according to claim 1.
(4) The invention according to claim 4 is characterized in that the supercritical formation step uses at least one selected from the group consisting of argon, helium, neon and xenon as a carrier gas. It is a manufacturing method of a body.
(5) The invention according to claim 5 is the method for producing a polycrystalline body according to claim 1, wherein the group 14 element of the periodic table is selected from silicon (Si) and germanium (Ge).
(6) The invention according to claim 6 is the method for producing a polycrystal according to claim 1, wherein the halide of the group 14 element of the periodic table is chloride or bromide.
(7) The invention according to claim 7 is the method for producing a polycrystalline body according to claim 1, wherein the halide of the group 14 element of the periodic table is silicon tetrachloride.
（８）請求項８に係る発明は、前記反応容器中の圧力が３ＭＰａ以上、当該反応容器中の温度が８０Ｋ以上に保持されることを特徴とする請求項１に記載の多結晶体の製造方法である。
（９）請求項９に係る発明は、前記プラズマ放電工程において、種結晶上に周期表１４族元素の多結晶体を析出させることを特徴とする請求項１に記載の多結晶体の製造方法である。
（１０）請求項１０に係る発明は、前記種結晶の温度を４５０Ｋ以上に保持することを特徴とする請求項９に記載の多結晶体の製造方法である。 (8) The invention according to claim 8 is characterized in that the pressure in the reaction vessel is maintained at 3 MPa or higher and the temperature in the reaction vessel is maintained at 80 K or higher. Is the method.
(9) The invention according to claim 9 is characterized in that in the plasma discharge step, a polycrystalline body of a group 14 element of the periodic table is precipitated on a seed crystal. It is.
(10) The invention according to claim 10 is the method for producing a polycrystalline body according to claim 9, wherein the temperature of the seed crystal is maintained at 450K or higher.
（１１）請求項１１に係る発明は、前記プラズマ放電工程において、周期表１４族元素の多結晶体を、当該周期表１４族元素の多結晶体の融点より高い温度に保持された析出用部材上に析出させ、且つ、析出した当該周期表１４族元素の多結晶体を融解させることを特徴とする請求項１に記載の多結晶体の製造方法である。
（１２）請求項１２に係る発明は、前記析出用部材の温度を１，８００Ｋ以上に保持することを特徴とする請求項１１に記載の多結晶体の製造方法である。
（１３）請求項１３に係る発明は、前記周期表１４族元素の多結晶体が、ポリシリコンであることを特徴とする請求項１に記載の多結晶体の製造方法である。 (11) According to an eleventh aspect of the present invention, in the plasma discharge step, the polycrystalline member of the periodic table group 14 element is maintained at a temperature higher than the melting point of the polycrystalline member of the periodic table group 14 element. The method for producing a polycrystalline body according to claim 1, wherein the polycrystalline body of the group 14 element of the periodic table is precipitated and melted.
(12) The invention according to claim 12 is the method for producing a polycrystalline body according to claim 11, wherein the temperature of the precipitation member is maintained at 1800 K or more.
(13) The invention according to claim 13 is the method for producing a polycrystal according to claim 1, wherein the polycrystal of the group 14 element of the periodic table is polysilicon.
（１４）請求項１４に係る発明は、ポリシリコンの製造装置であって、内部に導入されたハロゲン化ケイ素化合物の超臨界流体状態を形成するための反応容器本体と、前記反応容器本体の内部に設けられプラズマ放電を行うための電極と、前記反応容器本体の内部に設けられ前記プラズマ放電で分解したシリコンを当該シリコンの融点より高い温度に保持された表面上で析出させ、且つ、析出した当該シリコンを融解させる析出用部材と、前記析出用部材上で融解した前記シリコンを回収する回収部材と、を備えることを特徴とするポリシリコンの製造装置である。
（１５）請求項１５に係る発明は、前記析出用部材は、漏斗状の形状を有し、円錐形の本体部分と、当該本体部分の表面上で析出し且つ融解した前記シリコンを当該本体部分の下方に流下させるように形成された管状部分と、を有することを特徴とする請求項１４に記載のポリシリコンの製造装置である。
（１６）請求項１６に係る発明は、前記析出用部材は、グラファイトから構成されることを特徴とする請求項１４に記載のポリシリコンの製造装置である。 (14) The invention according to claim 14 is an apparatus for producing polysilicon, wherein a reaction vessel body for forming a supercritical fluid state of a silicon halide compound introduced therein, and the inside of the reaction vessel body An electrode for performing plasma discharge, and silicon decomposed by the plasma discharge provided inside the reaction vessel main body and deposited on a surface maintained at a temperature higher than the melting point of the silicon, and deposited A polysilicon manufacturing apparatus comprising: a deposition member that melts the silicon; and a recovery member that collects the silicon melted on the deposition member.
(15) In the invention according to claim 15, the deposition member has a funnel-like shape, and the main body portion includes a conical main body portion and the silicon deposited and melted on the surface of the main body portion. The apparatus for producing polysilicon according to claim 14, further comprising: a tubular portion formed so as to flow downward.
(16) The invention according to claim 16 is the polysilicon manufacturing apparatus according to claim 14, wherein the deposition member is made of graphite.
　本発明によれば、周期表１４族元素の多結晶体が高速で得られる。特に、ポリシリコンは、単結晶シリコンと同様な高結晶性を有する。 According to the present invention, a polycrystal of a periodic table group 14 element can be obtained at high speed. In particular, polysilicon has high crystallinity similar to that of single crystal silicon.
本実施の形態が適用される周期表１４族元素の多結晶体の製造方法を実施するための製造装置の一例を説明する図である。It is a figure explaining an example of the manufacturing apparatus for enforcing the manufacturing method of the polycrystal of the periodic table 14 group element to which this Embodiment is applied. 四塩化ケイ素とアルゴンガスとの混合物の超臨界流体状態におけるプラズマ発光スペクトルを示す。The plasma emission spectrum in the supercritical fluid state of the mixture of silicon tetrachloride and argon gas is shown. 電極の表面に形成された球状の多結晶シリコンのＳＥＭ像である。It is a SEM image of spherical polycrystalline silicon formed on the surface of an electrode. 電極の表面に形成された球状の多結晶シリコンのＥＤＸマップ像とＥＤＸチャートである。It is an EDX map image and EDX chart of spherical polycrystalline silicon formed on the surface of an electrode. 図３に示す球状部分の近傍に形成された膜状の多結晶シリコンのＳＥＭ像である。It is a SEM image of the film-like polycrystalline silicon formed in the vicinity of the spherical part shown in FIG. 電極表面に形成された多結晶シリコンのラマン分光スペクトルを示す。The Raman spectrum of the polycrystalline silicon formed in the electrode surface is shown. 第２の実施の形態を説明する図である。It is a figure explaining 2nd Embodiment. 第３の実施の形態を説明する図である。It is a figure explaining 3rd Embodiment. 析出用部材を説明する図である。It is a figure explaining the member for precipitation.
　以下、本発明の実施の形態について詳細に説明する。尚、本発明は、以下の実施の形態に限定されるものではなく、その要旨の範囲内で種々変形して実施することが出来る。また、使用する図面は本実施の形態を説明するためのものであり、実際の大きさを表すものではない。 Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. The drawings used are for explaining the present embodiment and do not represent the actual size.
（第１の実施の形態）
　図１は、本実施の形態が適用される多結晶体の製造方法を実施するための製造装置の一例を説明する図である。
　図１に示すように、製造装置Ｉは、後述する周期表１４族元素のハロゲン化物の超臨界流体状態を保つことが可能な耐圧を有する反応容器１１０と、反応容器１１０内で形成される超臨界流体状態においてプラズマ放電を発生させるために平行に配置された１対の電極１１１，１２１と、反応容器１１０内に供給される周期表１４族元素のハロゲン化物を貯蔵する原料貯槽２１と、反応容器１１０内に供給されるキャリアガスを貯蔵するキャリアガス貯槽２２と、を有している。 (First embodiment)
FIG. 1 is a diagram for explaining an example of a production apparatus for carrying out a method for producing a polycrystalline body to which the present embodiment is applied.
As shown in FIG. 1, the manufacturing apparatus I includes a reaction vessel 110 having a pressure resistance capable of maintaining a supercritical fluid state of a halide of a periodic table 14 group element, which will be described later, and a super vessel formed in the reaction vessel 110. A pair of electrodes 111 and 121 arranged in parallel to generate a plasma discharge in a critical fluid state, a raw material storage tank 21 for storing a halide of a group 14 element of the periodic table supplied into the reaction vessel 110, a reaction And a carrier gas storage tank 22 for storing the carrier gas supplied into the container 110.
　図１に示すように、電極１１１，１２１には、プラズマ放電のための電力を供給する高周波電源２７が整合器２６を介して接続されている。本実施の形態では、原料貯槽２１内に貯蔵された周期表１４族元素のハロゲン化物は、原料供給弁２１ａを開き、恒温機２３により温度が調整され、所定の供給機２４により原料供給管２１Ｌを介して反応容器１１０に供給される。
　キャリアガス貯槽２２内に貯蔵されたキャリアガスは、圧力調整弁２２ａを開きガス供給管２２Ｌを介して反応容器１１０に供給される。反応容器１１０内の圧力は、排圧管１０Ｌを介して排圧調整弁２５により調整している。
　本実施の形態では、反応容器１１０内の電極１１１，１２１の近傍に、周期表１４族元素の多結晶体を積層させるための基板３０と、基板３０を所定の温度に保持するための加熱器３１とを設けている。
　尚、図示しないが、反応容器１１０を所定の温度に加熱するための加熱装置が設けられている。加熱装置としては、所定の熱媒を使用するジャケット式加熱器、カートリッジ式ヒータ等が挙げられる。また、反応容器１１０を恒温槽内に設置してもよい。 As shown in FIG. 1, a high frequency power source 27 that supplies power for plasma discharge is connected to the electrodes 111 and 121 via a matching unit 26. In the present embodiment, the halide of the group 14 element of the periodic table stored in the raw material storage tank 21 opens the raw material supply valve 21a, the temperature is adjusted by the thermostatic device 23, and the predetermined supply device 24 supplies the raw material supply pipe 21L. To be supplied to the reaction vessel 110.
The carrier gas stored in the carrier gas storage tank 22 is supplied to the reaction vessel 110 through the gas supply pipe 22L by opening the pressure adjustment valve 22a. The pressure in the reaction vessel 110 is adjusted by the exhaust pressure adjusting valve 25 through the exhaust pressure pipe 10L.
In the present embodiment, a substrate 30 for laminating a polycrystal of a group 14 element of the periodic table in the vicinity of the electrodes 111 and 121 in the reaction vessel 110 and a heater for maintaining the substrate 30 at a predetermined temperature. 31 is provided.
Although not shown, a heating device for heating the reaction vessel 110 to a predetermined temperature is provided. Examples of the heating device include a jacket type heater and a cartridge type heater using a predetermined heat medium. Moreover, you may install the reaction container 110 in a thermostat.
　電極１１１，１２１を構成する材料は、プラズマ放電が可能な材料であれば特に限定されない。例えば、純金属電極を構成する材料としては、マンガン、鉄、コバルト、ニッケル、銅、亜鉛、銀、スズ、アルミニウム、タングステン、白金、金等が挙げられる。被めっき電極を構成する材料としては、銀めっき鉄、亜鉛めっき鉄、スズめっき鉄等が挙げられる。合金電極を構成する材料としては、真鍮、鉄ニッケル合金、鉄コバルト合金、マグネシウム合金等が挙げられる。これらの中でも、マンガン、銅、亜鉛、白金、金、亜鉛めっき鉄、真鍮、が好ましい。
　また、電極１１１，１２１の電極間距離は、反応容器１１０内の温度、圧力又は放電条件によって選択され、特に限定されない。本実施の形態では、電極間距離は、０．００２ｍｍ～５ｍｍの範囲内で設定される。尚、本実施の形態では、電極１１１，１２１の先端部分が取り外し可能になっている。電極１１１，１２１の先端部分は、例えば、炭素鋼を用いて構成されている。 The material constituting the electrodes 111 and 121 is not particularly limited as long as it is a material capable of plasma discharge. For example, the material constituting the pure metal electrode includes manganese, iron, cobalt, nickel, copper, zinc, silver, tin, aluminum, tungsten, platinum, gold, and the like. Examples of the material constituting the electrode to be plated include silver-plated iron, galvanized iron, and tin-plated iron. Examples of the material constituting the alloy electrode include brass, iron nickel alloy, iron cobalt alloy, and magnesium alloy. Among these, manganese, copper, zinc, platinum, gold, galvanized iron, and brass are preferable.
Further, the distance between the electrodes 111 and 121 is selected according to the temperature, pressure or discharge conditions in the reaction vessel 110 and is not particularly limited. In the present embodiment, the distance between the electrodes is set within a range of 0.002 mm to 5 mm. In the present embodiment, the tip portions of the electrodes 111 and 121 are removable. The tip portions of the electrodes 111 and 121 are made of, for example, carbon steel.
　反応容器１１０を構成する材料は、周期表１４族元素のハロゲン化物の超臨界流体状態を保つことが可能な材料であれば特に限定されない。例えば、ステンレス等が挙げられる。本実施の形態では、塩素ガスによる腐食を考慮し、ハステロイＣ（登録商標）を使用している。
　基板３０を構成する材料は、周期表１４族元素の多結晶体を積層させることが可能であれば特に限定されず、本実施の形態では、ＳＵＳ製基板を使用している。基板３０は、加熱器３１により加熱され、通常、４００℃～５００℃程度の温度に保持されている。
　キャリアガスは、原料として使用する周期表１４族元素のハロゲン化物に対し不活性であるものが好ましく、例えば、ヘリウム、ネオン、アルゴン等が挙げられる。本実施の形態では、キャリアガスとしてアルゴンを使用している。 The material constituting the reaction vessel 110 is not particularly limited as long as the material can maintain the supercritical fluid state of the halide of the group 14 element of the periodic table. For example, stainless steel can be used. In this embodiment, Hastelloy C (registered trademark) is used in consideration of corrosion by chlorine gas.
The material composing the substrate 30 is not particularly limited as long as it is possible to stack a polycrystal of the group 14 element of the periodic table, and in this embodiment, a SUS substrate is used. The substrate 30 is heated by a heater 31 and is usually maintained at a temperature of about 400 ° C. to 500 ° C.
The carrier gas is preferably inert to the halide of the Group 14 element used as a raw material, and examples thereof include helium, neon, and argon. In this embodiment, argon is used as the carrier gas.
（周期表１４族元素のハロゲン化物）
　次に、本実施の形態において原料として使用する周期表１４族元素のハロゲン化物について説明する。
　本実施の形態で使用する周期表１４族元素のハロゲン化物としては、ハロゲン化炭素化合物、ハロゲン化ケイ素化合物、ハロゲン化ゲルマニウム化合物等が挙げられる。これらの中でも、ハロゲン化ケイ素化合物、ハロゲン化ゲルマニウム化合物が好ましく、さらに、ハロゲン化ケイ素化合物が特に好ましい。 (Halides of group 14 elements of the periodic table)
Next, the halides of group 14 elements of the periodic table used as raw materials in the present embodiment will be described.
Examples of the halide of the group 14 element in the periodic table used in this embodiment include a halogenated carbon compound, a halogenated silicon compound, and a halogenated germanium compound. Among these, a halogenated silicon compound and a halogenated germanium compound are preferable, and a silicon halide compound is particularly preferable.
（ハロゲン化ケイ素化合物）
　ハロゲン化ケイ素化合物としては、フッ化ケイ素、塩化ケイ素、臭化ケイ素、ヨウ化ケイ素が挙げられる。これらの中でも、塩化ケイ素、臭化ケイ素が好ましい。
　塩化ケイ素としては、例えば、テトラクロルシラン（ＳｉＣｌ４）、ヘキサクロルジシラン、オクタクロルトリシラン、デカクロルトリシラン、ドデカクロルペンタシラン等が挙げられる。また、クロルシラン（ＳｉＨ３Ｃｌ）、ジクロルシラン（ＳｉＨ２Ｃｌ２）、トリクロルシラン（ＳｉＨＣｌ３）等のシラン誘導体が挙げられる。
　臭化ケイ素としては、四臭化ケイ素（ＳｉＢｒ４）、六臭化二ケイ素、八臭化三ケイ素、十臭化四ケイ素等が挙げられる。
　さらに、臭化三塩化ケイ素、二臭化二塩化ケイ素、三臭化塩化ケイ素、ヨウ化三塩化ケイ素、塩化硫化水素ケイ素、ヘキサクロルジシロキサン等も挙げられる。
　これらのなかでも、テトラクロルシラン（ＳｉＣｌ４）が特に好ましい。 (Halogenated silicon compounds)
Examples of the silicon halide compound include silicon fluoride, silicon chloride, silicon bromide, and silicon iodide. Among these, silicon chloride and silicon bromide are preferable.
Examples of silicon chloride include tetrachlorosilane (SiCl 4 ), hexachlorodisilane, octachlorotrisilane, decachlorotrisilane, dodecachloropentasilane, and the like. Further, silane derivatives such as chlorosilane (SiH 3 Cl), dichlorosilane (SiH 2 Cl 2 ), and trichlorosilane (SiHCl 3 ) can be given.
Examples of silicon bromide include silicon tetrabromide (SiBr 4 ), disilicon hexabromide, trisilicon octabromide, tetrasilicon decabromide and the like.
Furthermore, silicon bromide trichloride, silicon dibromide dichloride, silicon tribromide chloride, silicon iodide trichloride, silicon chlorosulfide, hexachlorodisiloxane and the like can be mentioned.
Among these, tetrachlorosilane (SiCl 4 ) is particularly preferable.
（ハロゲン化ゲルマニウム化合物）
　ハロゲン化ゲルマニウム化合物としては、フッ化ゲルマニウム、塩化ゲルマニウム、臭化ゲルマニウム、ヨウ化ゲルマニウムが挙げられる。これらの中でも、塩化ゲルマニウム、臭化ゲルマニウムが好ましい。
　塩化ゲルマニウムとしては、二塩化ゲルマニウム、四塩化ゲルマニウムが挙げられる。臭化ゲルマニウムとしては、二臭化ゲルマニウム、四臭化ゲルマニウムが挙げられる。 (Halogenated germanium compound)
Examples of the halogenated germanium compound include germanium fluoride, germanium chloride, germanium bromide, and germanium iodide. Among these, germanium chloride and germanium bromide are preferable.
Examples of germanium chloride include germanium dichloride and germanium tetrachloride. Examples of germanium bromide include germanium dibromide and germanium tetrabromide.
　尚、本実施の形態において、原料として使用する周期表１４族元素のハロゲン化物が固体の場合、予め原料を所定の溶媒に溶解させた溶液を調製し、この溶液を反応容器１１０に供給することもできる。使用可能な溶媒は、周期表１４族元素のハロゲン化物を溶解するものであれば特に限定されない。好ましくは、後述する超臨界流体状態におけるその溶媒に固有の臨界温度、臨界圧力を考慮し、公知の物質の中から選択する。具体例として、二酸化炭素、３フッ化メタン（フルオロホルム）、エタン、プロパン、ブタン、ベンゼン、メチルエーテル、クロロホルム等が挙げられる。 In this embodiment, when the halide of the group 14 element of the periodic table used as a raw material is solid, a solution in which the raw material is dissolved in a predetermined solvent is prepared in advance, and this solution is supplied to the reaction vessel 110. You can also. The solvent that can be used is not particularly limited as long as it can dissolve a halide of a group 14 element of the periodic table. Preferably, the material is selected from known materials in consideration of the critical temperature and critical pressure inherent to the solvent in the supercritical fluid state described later. Specific examples include carbon dioxide, trifluoromethane (fluoroform), ethane, propane, butane, benzene, methyl ether, chloroform and the like.
（多結晶体の製造方法）
　次に、上述した製造装置Ｉを用いて周期表１４族元素の多結晶体を製造する方法について説明する。本実施の形態では、周期表１４族元素のハロゲン化物としてテトラクロルシラン（ＳｉＣｌ４）を使用し、キャリアガスとしてアルゴンを使用し、多結晶シリコンを製造する例について説明する。 (Polycrystalline production method)
Next, a method for producing a polycrystal of a periodic table group 14 element using the production apparatus I described above will be described. In this embodiment, an example in which polycrystalline silicon is manufactured using tetrachlorosilane (SiCl 4 ) as a halide of a group 14 element of the periodic table and argon as a carrier gas will be described.
　本実施の形態では、初めに、圧力調整弁２２ａを開き、キャリアガス貯槽２２に貯蔵されているアルゴンを、ガス供給管２２Ｌを介して反応容器１１０に供給する。続いて、原料供給弁２１ａを開き、原料貯槽２１に貯蔵されているテトラクロルシランを供給機２４により原料供給管２１Ｌを介して反応容器１１０に供給する。本実施の形態では、供給機２４として送液ポンプを使用している。テトラクロルシランは、反応容器１１０に供給される前に、恒温機２３により所定の温度に調整される。これにより、目的とする圧力まで速やかに加圧し、圧力を安定させることができる。恒温機２３により温度が調整されるテトラクロルシランの温度は特に限定されないが、本実施の形態では、通常２５℃～３００℃、好ましくは、６０℃～２５０℃の範囲である。 In the present embodiment, first, the pressure regulating valve 22a is opened, and argon stored in the carrier gas storage tank 22 is supplied to the reaction vessel 110 through the gas supply pipe 22L. Subsequently, the raw material supply valve 21a is opened, and tetrachlorosilane stored in the raw material storage tank 21 is supplied to the reaction vessel 110 by the supply device 24 via the raw material supply pipe 21L. In the present embodiment, a liquid feed pump is used as the feeder 24. Tetrachlorosilane is adjusted to a predetermined temperature by the thermostat 23 before being supplied to the reaction vessel 110. Thereby, it can pressurize rapidly to the target pressure and can stabilize a pressure. The temperature of the tetrachlorosilane whose temperature is adjusted by the thermostat 23 is not particularly limited, but in the present embodiment, it is usually in the range of 25 to 300 ° C., preferably 60 to 250 ° C.
　反応容器１１０に供給するテトラクロルシランとアルゴンとの割合は特に限定されない。本実施の形態では、アルゴン５０ｍｌに対し、テトラクロルシラン０．１ｍｌ～１００，０００ｍｌ、好ましくは、１０ｍｌ～５，０００ｍｌ、より好ましくは、１０ｍｌ～２００ｍｌである。アルゴンに対するテトラクロルシランの割合が過度に小さいと、ポリシリコンの生成速度が遅くなる傾向がある。アルゴンに対するテトラクロルシランの割合が過度に大きいと、プラズマ放電が不安定となる傾向がある。 The ratio of tetrachlorosilane and argon supplied to the reaction vessel 110 is not particularly limited. In this embodiment mode, the amount of tetrachlorosilane is 0.1 ml to 100,000 ml, preferably 10 ml to 5,000 ml, more preferably 10 ml to 200 ml with respect to 50 ml of argon. When the ratio of tetrachlorosilane to argon is excessively small, the production rate of polysilicon tends to be slow. If the ratio of tetrachlorosilane to argon is excessively large, the plasma discharge tends to become unstable.
　尚、テトラクロルシランとアルゴンとが供給された反応容器１１０内の圧力は、圧力調整弁２２ａ及び排圧調整弁２５を用いて調整する。反応容器１１０内の圧力は特に限定されないが、本実施の形態では、通常、３ＭＰａ～２０ＭＰａ、好ましくは、５ＭＰａ～１０ＭＰａの範囲で調整する。 Note that the pressure in the reaction vessel 110 to which tetrachlorosilane and argon are supplied is adjusted using the pressure regulating valve 22a and the exhaust pressure regulating valve 25. The pressure in the reaction vessel 110 is not particularly limited, but in the present embodiment, it is usually adjusted in the range of 3 MPa to 20 MPa, preferably 5 MPa to 10 MPa.
　次に、所定の加熱器（図示せず）を用いて反応容器１１０を加熱し、反応容器１１０に供給されたテトラクロルシランとアルゴンとの混合物の超臨界流体状態を形成する。
　ここで超臨界流体状態とは、物質固有の気液の臨界温度を超えた非凝縮性流体と定義される。即ち、密閉容器内に気体と液体とが存在すると、温度上昇とともに液体は熱膨張しその密度は低下する。一方、気体は、蒸気圧の増加によりその密度が増大する。そして最後に、両者の密度が等しくなり、気体とも液体とも区別の付かない均一な状態になる。物質の温度－圧力線図（図示せず）では、このような状態になる点を臨界点といい、臨界点の温度を臨界温度（Ｔｃ）、臨界点の圧力を臨界圧力（Ｐｃ）という。超臨界流体状態とは、物質の温度及び圧力が臨界点を超えた状態にあることをいう。 Next, the reaction vessel 110 is heated using a predetermined heater (not shown) to form a supercritical fluid state of a mixture of tetrachlorosilane and argon supplied to the reaction vessel 110.
Here, the supercritical fluid state is defined as a non-condensable fluid that exceeds the gas-liquid critical temperature inherent to the substance. That is, when gas and liquid are present in the sealed container, the liquid thermally expands as the temperature rises, and its density decreases. On the other hand, the density of gas increases as the vapor pressure increases. And finally, the density of both becomes equal, and it becomes a uniform state indistinguishable from gas and liquid. In the temperature-pressure diagram (not shown) of the substance, the point where such a state is reached is called the critical point, the critical point temperature is called the critical temperature (Tc), and the critical point pressure is called the critical pressure (Pc). A supercritical fluid state means that the temperature and pressure of a substance exceed a critical point.
　本実施の形態では、テトラクロルシランの臨界温度（Ｔｃ）は２３３．６℃（５０６．７５Ｋ）、臨界圧力（Ｐｃ）は３．７３ＭＰａである。また、アルゴンの臨界温度（Ｔｃ）は－１８５．７℃（８７．４５Ｋ）、臨界圧力（Ｐｃ）は４．８６ＭＰａである。
　テトラクロルシランとアルゴンとの混合物の場合、混合物の臨界温度（Ｔｃ）と臨界圧力（Ｐｃ）とは、テトラクロルシランとアルゴンの組成により、それぞれの物質の臨界温度（Ｔｃ）と臨界圧力（Ｐｃ）との間で調整することができる。 In the present embodiment, the tetrachlorosilane has a critical temperature (Tc) of 233.6 ° C. (506.75 K) and a critical pressure (Pc) of 3.73 MPa. The critical temperature (Tc) of argon is -185.7 ° C. (87.45 K), and the critical pressure (Pc) is 4.86 MPa.
In the case of a mixture of tetrachlorosilane and argon, the critical temperature (Tc) and critical pressure (Pc) of the mixture depend on the composition of tetrachlorosilane and argon, and the critical temperature (Tc) and critical pressure (Pc) of each substance. ) Can be adjusted between.
　本実施の形態では、反応容器１１０の温度は、通常、３００Ｋ～６００Ｋ、好ましくは、３１３Ｋ～５１０Ｋの範囲になるように加熱される。また、反応容器１１０内の圧力は、通常、４．８６ＭＰａ～４０ＭＰａ、好ましくは４ＭＰａ～１０ＭＰａの範囲で保持される。このような条件下、反応容器１１０内で、テトラクロルシランとアルゴンとの混合物の超臨界流体状態が形成される。 In the present embodiment, the temperature of the reaction vessel 110 is usually heated to be in the range of 300K to 600K, preferably 313K to 510K. Further, the pressure in the reaction vessel 110 is usually maintained in the range of 4.86 MPa to 40 MPa, preferably 4 MPa to 10 MPa. Under such conditions, a supercritical fluid state of a mixture of tetrachlorosilane and argon is formed in the reaction vessel 110.
　続いて、高周波電源２７により電極１１１，１２１間に電力を印加し、プラズマ放電を発生させる。プラズマ放電を発生させる放電条件は、電極１１１，１２１間の距離や反応容器１１０内の圧力により選択され特に限定されない。本実施の形態では、例えば、電源の周波数を１３．５６ＭＨｚ、電力を１００Ｗ～２００Ｗ程度に設定した場合、プラズマ放電時間は、数秒間～数時間程度とすることが適当である。 Subsequently, electric power is applied between the electrodes 111 and 121 by the high frequency power source 27 to generate plasma discharge. The discharge conditions for generating plasma discharge are not particularly limited and are selected depending on the distance between the electrodes 111 and 121 and the pressure in the reaction vessel 110. In the present embodiment, for example, when the power source frequency is set to 13.56 MHz and the power is set to about 100 W to 200 W, the plasma discharge time is suitably set to about several seconds to several hours.
　上述したように、テトラクロルシランとアルゴンとの混合物の超臨界流体状態において電極１１１，１２１間に電力を印加し、プラズマ放電を発生させることにより、テトラクロルシランは分解・反応し、反応容器１１０内に設けた基板３０の表面、電極１１１，１２１の表面、反応容器１１０の内壁表面に多結晶シリコンが形成される。 As described above, by applying electric power between the electrodes 111 and 121 in a supercritical fluid state of a mixture of tetrachlorosilane and argon to generate plasma discharge, the tetrachlorosilane is decomposed and reacted, and the reaction vessel 110. Polycrystalline silicon is formed on the surface of the substrate 30 provided inside, the surfaces of the electrodes 111 and 121, and the inner wall surface of the reaction vessel 110.
　本実施の形態では、超臨界流体状態のテトラクロルシランにプラズマ放電を行うことにより、高濃度のケイ素ラジカルが発生し、高密度の多結晶シリコンが生成する。
　また、超臨界流体状態のテトラクロルシランは、高い拡散性を有するため、基板３０等の表面にケイ素ラジカルが効率よく供給される。さらに、テトラクロルシランとアルゴンとの混合物の超臨界流体状態を形成することにより、反応系内が均一濃度に保たれ、生成する多結晶シリコンの緻密性が向上する。 In this embodiment mode, by performing plasma discharge on tetrachlorosilane in a supercritical fluid state, high concentration silicon radicals are generated and high density polycrystalline silicon is generated.
Further, since tetrachlorosilane in a supercritical fluid state has high diffusibility, silicon radicals are efficiently supplied to the surface of the substrate 30 and the like. Furthermore, by forming a supercritical fluid state of a mixture of tetrachlorosilane and argon, the inside of the reaction system is maintained at a uniform concentration, and the density of the produced polycrystalline silicon is improved.
　尚、本実施の形態では、プラズマ放電を行う際に高周波電源２７を用いる場合について説明したが、これに代えて直流電源を用いることもできる。高周波電源２７の場合には、多結晶シリコンが両方の電極等に生成するが、直流電源を用いると、一方の電極（陰極）又は一方の電極近傍に設けた所定の基材上に効率良く多結晶シリコンが生成する。 In the present embodiment, the case where the high-frequency power source 27 is used when performing plasma discharge has been described, but a DC power source may be used instead. In the case of the high-frequency power source 27, polycrystalline silicon is generated on both electrodes and the like. However, when a DC power source is used, a large amount of polycrystalline silicon is efficiently formed on one electrode (cathode) or on a predetermined substrate provided near one electrode. Crystalline silicon is produced.
（第２の実施の形態）
　図７は、第２の実施の形態を説明する図である。第１の実施の形態（図１）で説明した製造装置Ｉと同様な構成については同じ符号を用い、その説明を省略する。
　図７に示す製造装置ＩＩは、周期表１４族元素のハロゲン化物の超臨界流体状態を保つことが可能な耐圧を有する反応容器（反応容器本体）１２０と、反応容器１２０内で形成される超臨界流体状態においてプラズマ放電を発生させるために平行に配置された１対の電極１１２，１２２と、反応容器１２０内に供給される周期表１４族元素のハロゲン化物を貯蔵する原料貯槽２１と、反応容器１２０内に供給されるキャリアガス（不活性ガス）を貯蔵するキャリアガス貯槽２２と、を有している。 (Second Embodiment)
FIG. 7 is a diagram for explaining the second embodiment. The same reference numerals are used for the same components as those of the manufacturing apparatus I described in the first embodiment (FIG. 1), and the description thereof is omitted.
The manufacturing apparatus II shown in FIG. 7 includes a reaction vessel (reaction vessel body) 120 having a pressure resistance capable of maintaining a supercritical fluid state of a halide of a group 14 element of the periodic table, and a super vessel formed in the reaction vessel 120. A pair of electrodes 112 and 122 arranged in parallel to generate a plasma discharge in a critical fluid state, a raw material storage tank 21 for storing a halide of a group 14 element of the periodic table supplied into the reaction vessel 120, a reaction And a carrier gas storage tank 22 for storing a carrier gas (inert gas) supplied into the container 120.
　図７に示すように、電極１１２，１２２には、プラズマ放電のための電力を供給する高周波電源２７が整合器２６を介して接続されている。本実施の形態では、原料貯槽２１内に貯蔵された周期表１４族元素のハロゲン化物は、原料供給弁２１ａを開き、恒温機２３により温度が調整され、所定の供給機２４により原料供給管２１Ｌを介して反応容器１２０に供給される。キャリアガス貯槽２２内に貯蔵されたキャリアガスは、圧力調整弁２２ａを開きガス供給管２２Ｌを介して反応容器１２０に供給される。反応容器１２０内の圧力は、排圧調整弁２５により調整している。 As shown in FIG. 7, a high frequency power supply 27 that supplies power for plasma discharge is connected to the electrodes 112 and 122 via a matching unit 26. In the present embodiment, the halide of the group 14 element of the periodic table stored in the raw material storage tank 21 opens the raw material supply valve 21a, the temperature is adjusted by the thermostatic device 23, and the predetermined supply device 24 supplies the raw material supply pipe 21L. To be supplied to the reaction vessel 120. The carrier gas stored in the carrier gas storage tank 22 is supplied to the reaction vessel 120 through the gas supply pipe 22L by opening the pressure adjustment valve 22a. The pressure in the reaction vessel 120 is adjusted by the exhaust pressure adjustment valve 25.
　本実施の形態では、反応容器１２０内の電極１１２，１２２の近傍に、周期表１４族元素の多結晶体を析出させるための種結晶４０を設けている。反応容器１２０外には、種結晶４０の両端部に取り付けた炭素電極４１に所定の電圧を印加する外部電源４２と、を設けている。 In the present embodiment, a seed crystal 40 is provided in the vicinity of the electrodes 112 and 122 in the reaction vessel 120 for precipitating a polycrystal of a group 14 element of the periodic table. Outside the reaction vessel 120, an external power source 42 for applying a predetermined voltage to the carbon electrodes 41 attached to both ends of the seed crystal 40 is provided.
　図７に示すように、本実施の形態では、種結晶４０は両端部が反応容器１２０の底部に固定され、逆Ｕ字状に形成された中間部が電極１１２，１２２側に向くように取り付けられている。種結晶４０の両端部には、それぞれ炭素電極４１が接合され、これらは反応容器１２０の外部に設けた外部電源４２と電気的に接合されている。
　種結晶４０を構成する材料は、析出させる周期表１４族元素の単結晶が好ましく、例えば、シリコン単結晶、ゲルマニウム単結晶等が挙げられる。さらに、炭化ケイ素（ＳｉＣ）等も使用可能である。後述するように、種結晶４０の表面に到達した周期表１４族元素のラジカルは、種結晶４０により結晶化を誘発され、固相エピタキシャル成長が起こり、最終的に多結晶体が得られると考えられる。 As shown in FIG. 7, in the present embodiment, the seed crystal 40 is attached so that both ends are fixed to the bottom of the reaction vessel 120 and the intermediate portion formed in an inverted U shape faces the electrodes 112 and 122 side. It has been. Carbon electrodes 41 are joined to both ends of the seed crystal 40, and these are electrically joined to an external power source 42 provided outside the reaction vessel 120.
The material constituting the seed crystal 40 is preferably a single crystal of a group 14 element of the periodic table to be precipitated, and examples thereof include a silicon single crystal and a germanium single crystal. Further, silicon carbide (SiC) or the like can be used. As will be described later, the radical of the group 14 element of the periodic table that has reached the surface of the seed crystal 40 is induced to be crystallized by the seed crystal 40, and solid-phase epitaxial growth occurs, so that a polycrystalline body is finally obtained. .
　周期表１４族元素が析出する種結晶４０の大きさは特に限定されないが、本実施の形態では、一片５ｍｍ程度の角柱を逆Ｕ字状に曲げ、高さ約２０ｍｍ程度になるように形成している。尚、種結晶として、粒径数ｎｍ～数百ｎｍ程度の結晶粒子を使用することもできる。
　種結晶４０の両端部に取り付けた炭素電極４１を構成する材料は、特に限定されない。本実施の形態では、カーボン電極材を使用している。 The size of the seed crystal 40 on which the periodic table group 14 element is deposited is not particularly limited, but in the present embodiment, a square column of about 5 mm in one piece is bent into an inverted U shape and formed to have a height of about 20 mm. ing. As seed crystals, crystal grains having a particle size of about several nm to several hundreds nm can be used.
The material which comprises the carbon electrode 41 attached to the both ends of the seed crystal 40 is not specifically limited. In the present embodiment, a carbon electrode material is used.
　また、種結晶４０は、種結晶４０の両端部に取り付けた炭素電極４１に外部電源４２を用いて電圧を印加することにより、通常、４５０Ｋ（４７３℃）以上、好ましくは５００Ｋ（２７３℃）以上の温度に保持されている。但し、例えば、周期表１４族元素がケイ素（Ｓｉ）の場合、ポリシリコンの融点１，６８７Ｋ（１，４１４℃）未満の温度に保たれる。 The seed crystal 40 is usually 450 K (473 ° C.) or higher, preferably 500 K (273 ° C.) or higher, by applying a voltage to the carbon electrodes 41 attached to both ends of the seed crystal 40 using an external power source 42. Is kept at a temperature of However, for example, when the group 14 element of the periodic table is silicon (Si), the temperature is kept at a temperature lower than the melting point of 1,687 K (1,414 ° C.) of polysilicon.
（ポリシリコンの製造方法）
　次に、上述した製造装置ＩＩにおいて、周期表１４族元素のハロゲン化物として四塩化ケイ素（ＳｉＣｌ４）を使用し、キャリアガスとしてアルゴンを使用し、多結晶シリコン（ポリシリコン）を製造する例について説明する。
　製造装置ＩＩ内では、四塩化ケイ素とアルゴンとの混合物の超臨界流体状態において電極１１２，１２２間に電力を印加し、プラズマ放電を発生させることにより、四塩化ケイ素は分解・反応する。そして、分解後に反応容器１２０内に設けたシリコン単結晶からなる種結晶４０の表面に到達したケイ素ラジカルは、種結晶４０の表面上で析出する。そして、種結晶４０のシリコン単結晶によって結晶化が誘発され、固相エピタキシャル成長が起こり、最終的にポリシリコンが形成される。ここで、種結晶４０としてシリコン単結晶を用いることにより、ポリシリコンの成長が促進される。 (Polysilicon production method)
Next, in the manufacturing apparatus II described above, an example of manufacturing polycrystalline silicon (polysilicon) using silicon tetrachloride (SiCl 4 ) as the halide of the group 14 element of the periodic table and argon as the carrier gas. explain.
In the production apparatus II, silicon tetrachloride is decomposed and reacted by applying electric power between the electrodes 112 and 122 in a supercritical fluid state of a mixture of silicon tetrachloride and argon to generate plasma discharge. Then, silicon radicals that have reached the surface of the seed crystal 40 made of a silicon single crystal provided in the reaction vessel 120 after decomposition are deposited on the surface of the seed crystal 40. Then, crystallization is induced by the silicon single crystal of the seed crystal 40, solid phase epitaxial growth occurs, and finally polysilicon is formed. Here, the growth of polysilicon is promoted by using a silicon single crystal as the seed crystal 40.
（第３の実施の形態）
　図８は、第３の実施の形態を説明する図である。第１の実施の形態（図１）で説明した製造装置Ｉと同様な構成については同じ符号を用い、その説明を省略する。
　図８に示すように、製造装置ＩＩＩは、ハロゲン化ケイ素化合物の一つである四塩化ケイ素の超臨界流体状態を保つことが可能な耐圧を有する反応容器（反応容器本体）１３０と、反応容器１３０内で形成される超臨界流体状態においてプラズマ放電を発生させるために平行に配置された１対の電極１１３，１２３と、反応容器１３０内に供給される四塩化ケイ素を貯蔵する原料貯槽２１と、反応容器１３０内に供給されるキャリアガス（不活性ガス）を貯蔵するキャリアガス貯槽２２と、を有している。 (Third embodiment)
FIG. 8 is a diagram for explaining the third embodiment. The same reference numerals are used for the same components as those of the manufacturing apparatus I described in the first embodiment (FIG. 1), and the description thereof is omitted.
As shown in FIG. 8, the manufacturing apparatus III includes a reaction vessel (reaction vessel body) 130 having a pressure resistance capable of maintaining a supercritical fluid state of silicon tetrachloride, which is one of silicon halide compounds, and a reaction vessel. A pair of electrodes 113 and 123 arranged in parallel to generate a plasma discharge in a supercritical fluid state formed in 130, and a raw material storage tank 21 for storing silicon tetrachloride supplied into the reaction vessel 130, And a carrier gas storage tank 22 for storing a carrier gas (inert gas) supplied into the reaction vessel 130.
　本実施の形態では、反応容器１３０内の電極１１３，１２３の近傍に、ポリシリコンを析出し且つ融解させるための析出用部材５０を設けている。析出用部材５０は、保持具５１により反応容器１３０内の電極１１３，１２３の近傍に保持されている。析出用部材５０は、所定の加熱装置（図示せず）により、ポリシリコンの融点より高い温度になるように加熱される。本実施の形態では、析出用部材５０は約１，７００Ｋ（１，４２７℃）～２０００Ｋ（１，７２７℃）程度に加熱される。
　さらに、本実施の形態では、析出用部材５０の表面において析出・融解し、析出用部材５０の下方に流下したポリシリコンを回収する坩堝（回収部材）５２が設けられている。 In the present embodiment, a deposition member 50 for depositing and melting polysilicon is provided in the vicinity of the electrodes 113 and 123 in the reaction vessel 130. The deposition member 50 is held by the holder 51 in the vicinity of the electrodes 113 and 123 in the reaction vessel 130. Precipitation member 50 is heated to a temperature higher than the melting point of polysilicon by a predetermined heating device (not shown). In the present embodiment, the deposition member 50 is heated to about 1,700 K (1,427 ° C.) to about 2000 K (1,727 ° C.).
Furthermore, in the present embodiment, a crucible (recovery member) 52 is provided that recovers polysilicon that has precipitated and melted on the surface of the deposition member 50 and has flowed down to the deposition member 50.
　析出用部材５０を構成する材料は、ポリシリコンの融点より高い温度に保持することが可能であれば特に限定されない。本実施の形態では、高純度グラファイトを使用している。
　坩堝５２を構成する材料は特に限定されず、例えば、石英、グラファイト、ハステロイ合金等が挙げられる。また、坩堝５２堝壁面にはシリコン板等を貼り、コンタミを防ぐことが好ましい。尚、本実施の形態では、坩堝５２を構成する材料として、グラファイトまたは石英を使用している。 The material constituting the deposition member 50 is not particularly limited as long as it can be maintained at a temperature higher than the melting point of polysilicon. In the present embodiment, high purity graphite is used.
The material which comprises the crucible 52 is not specifically limited, For example, quartz, a graphite, a Hastelloy alloy etc. are mentioned. Further, it is preferable to attach a silicon plate or the like on the wall surface of the crucible 52 to prevent contamination. In the present embodiment, graphite or quartz is used as the material constituting the crucible 52.
（析出用部材５０）
　次に、析出用部材５０の構造について説明する。
　図９は、析出用部材５０を説明する図である。図９に示すように、析出用部材５０は、円錐形の本体部分５０ａと管状部分５０ｂからなる漏斗状の形状を有している。
　析出用部材５０の内部には、炭化ケイ素（ＳｉＣ）から構成された複数本の電熱線５０ｃが埋め込まれている。
　析出用部材５０は、複数本の電熱線５０ｃに所定の電源（図示せず）を用いて通電することにより、ポリシリコンの融点（約１，６８７Ｋ（１，４１４℃））より高い温度（通常、約１，８００Ｋ（１，５２７℃）以上）に保持される。このとき、析出用部材５０の表面に析出したポリシリコンは、液体状態のまま本体部分５０ａと管状部分５０ｂを経由して下方に流下する。 (Deposition member 50)
Next, the structure of the deposition member 50 will be described.
FIG. 9 is a diagram illustrating the deposition member 50. As shown in FIG. 9, the deposition member 50 has a funnel-like shape composed of a conical body portion 50a and a tubular portion 50b.
A plurality of heating wires 50 c made of silicon carbide (SiC) are embedded in the deposition member 50.
The deposition member 50 is energized to a plurality of heating wires 50c using a predetermined power source (not shown), so that the temperature is higher than the melting point of polysilicon (about 1,687 K (1,414 ° C.)) (usually normal). , About 1,800 K (1,527 ° C. or higher). At this time, the polysilicon deposited on the surface of the deposition member 50 flows downward through the main body portion 50a and the tubular portion 50b in a liquid state.
（ポリシリコンの製造方法）
　次に、上述した製造装置ＩＩＩでは、四塩化ケイ素とアルゴンとの混合物の超臨界流体状態において電極１１３，１２３間に電力を印加し、プラズマ放電を発生させることにより、四塩化ケイ素は分解・反応し、反応容器１３０内に設けた析出用部材５０の表面に析出する。
　析出用部材５０は、前述したように、内部に埋め込んだ複数本の電熱線５０ｃに通電することにより、ポリシリコンの融点（約１，６８７Ｋ（１，４１４℃））より高温の約１，８００Ｋ以上の温度に保持されている。このため、析出用部材５０の表面に析出したポリシリコンは、液体状態のまま析出用部材５０の上部の円錐形の本体部分５０ａと管状部分５０ｂを経由して下方に流下する。
　続いて、析出用部材５０の下方に流下したポリシリコンは、流下途中で冷却され、冷却されたポリシリコンは、本実施の形態では、通常、径０．５ｍｍ～１ｍｍ程度の粒状となって析出用部材５０の下方に設けられた坩堝５２中に回収される。 (Polysilicon production method)
Next, in the manufacturing apparatus III described above, silicon tetrachloride is decomposed and reacted by applying power between the electrodes 113 and 123 in a supercritical fluid state of a mixture of silicon tetrachloride and argon to generate plasma discharge. And deposited on the surface of the deposition member 50 provided in the reaction vessel 130.
As described above, the deposition member 50 is energized through a plurality of heating wires 50c embedded therein, so that the deposition member 50 has a temperature higher than the melting point of polysilicon (approximately 1,687 K (1,414 ° C.)) of approximately 1,800 K. The above temperature is maintained. For this reason, the polysilicon deposited on the surface of the deposition member 50 flows down through the conical body portion 50a and the tubular portion 50b above the deposition member 50 in a liquid state.
Subsequently, the polysilicon that has flowed down to the deposition member 50 is cooled in the middle of the flow, and the cooled polysilicon is usually precipitated in the form of particles having a diameter of about 0.5 mm to 1 mm in this embodiment. It is collected in a crucible 52 provided below the member 50 for use.
　以下、実施例に基づき本実施の形態についてさらに詳述する。但し、本発明はこれらの実施例に限定されるものではない。 Hereinafter, this embodiment will be described in more detail based on examples. However, the present invention is not limited to these examples.
（実施例）
　図１に示す製造装置Ｉを使用し、以下の操作により多結晶シリコン（ポリシリコン）を製造する。
　反応容器１１０として、通電可能なハステロイＣ製の耐圧セル（内容量：５０ｍｌ）を使用する。供給機２４として送液ポンプ（日本分光株式会社製）、ガス圧力調整弁２２ａとして全自動圧力調整弁（日本分光株式会社製）、排圧調整弁２５として全自動排圧調整弁（日本分光株式会社製）を用いる。
　電極１１１，１２１として、大きさが１０ｍｍ×２０ｍｍである平行平板電極を反応容器１１０に取付ける。電極１１１，１２１の材質として、真鍮、亜鉛めっき鉄、ＳＵＳをそれぞれ使用する。電極１１１，１２１の間隔を、０．０１ｍｍに設定する。
　高周波電源２７として、交流発生器（東京ハイパワー株式会社製ＰＳＧ－１３０１）、高周波発生器（東京ハイパワー株式会社製ＰＡ－１５０）及び直流変換器（東京ハイパワー株式会社製ＰＳ－３３０）を用い、整合器２６として東京ハイパワー株式会社製ＨＣ－２０００を用いる。
　原料貯槽２１に純度９９．９％の四塩化ケイ素を充填する。キャリアガス貯槽２２に、純度９９．９％のアルゴンガスを充填する。 (Example)
Using the manufacturing apparatus I shown in FIG. 1, polycrystalline silicon (polysilicon) is manufactured by the following operation.
As the reaction vessel 110, a pressure-resistant cell (internal capacity: 50 ml) made of Hastelloy C that can be energized is used. A liquid feeding pump (manufactured by JASCO Corporation) as the feeder 24, a fully automatic pressure adjusting valve (manufactured by JASCO Corporation) as the gas pressure adjusting valve 22a, and a fully automatic exhaust pressure adjusting valve (JASCO Corporation) as the exhaust pressure adjusting valve 25 Company).
As the electrodes 111 and 121, parallel plate electrodes having a size of 10 mm × 20 mm are attached to the reaction vessel 110. As materials for the electrodes 111 and 121, brass, galvanized iron, and SUS are used. The distance between the electrodes 111 and 121 is set to 0.01 mm.
As the high-frequency power source 27, an AC generator (PSG-1301 manufactured by Tokyo High Power Co., Ltd.), a high frequency generator (PA-150 manufactured by Tokyo High Power Co., Ltd.) and a DC converter (PS-330 manufactured by Tokyo High Power Co., Ltd.) are used. As the matching unit 26, HC-2000 manufactured by Tokyo High Power Co., Ltd. is used.
The raw material storage tank 21 is filled with silicon tetrachloride having a purity of 99.9%. The carrier gas storage tank 22 is filled with argon gas having a purity of 99.9%.
　初めに、反応容器１１０中にキャリアガス貯槽２２からアルゴンガスを供給し、続いて、原料貯槽２１から反応容器１１０中に四塩化ケイ素を供給する。次に、反応容器１１０中の圧力が５ＭＰａになるように加圧し、温度を３０８Ｋに昇温し、四塩化ケイ素とアルゴンガスとの混合物の超臨界流体状態を形成し、約２０分間放置する。
　続いて、四塩化ケイ素とアルゴンガスとの混合物の超臨界流体状態において、高周波電源２７（１３．５６ＭＨｚ）により、電極１１１，１２１に１００Ｗの電力を約３分間印加し、プラズマ放電を発生させる。その後、反応容器１１０を冷却し、反応容器１１０中の圧力を、０．１ＭＰａ／分の速度で減圧する。
　反応終了後、反応容器１１０内に設けた基板３０の表面、電極１１１，１２１の表面、反応容器１１０の内壁表面に多結晶シリコンが形成される。尚、多結晶シリコンは、電極１１１，１２１の材質として真鍮、亜鉛めっき鉄、ＳＵＳを用いた場合、いずれの場合も形成される。 First, argon gas is supplied from the carrier gas storage tank 22 into the reaction container 110, and then silicon tetrachloride is supplied from the raw material storage tank 21 into the reaction container 110. Next, the pressure in the reaction vessel 110 is increased to 5 MPa, the temperature is raised to 308 K, a supercritical fluid state of a mixture of silicon tetrachloride and argon gas is formed, and the mixture is left for about 20 minutes.
Subsequently, in a supercritical fluid state of a mixture of silicon tetrachloride and argon gas, 100 W of electric power is applied to the electrodes 111 and 121 by the high frequency power supply 27 (13.56 MHz) for about 3 minutes to generate plasma discharge. Thereafter, the reaction vessel 110 is cooled, and the pressure in the reaction vessel 110 is reduced at a rate of 0.1 MPa / min.
After completion of the reaction, polycrystalline silicon is formed on the surface of the substrate 30 provided in the reaction vessel 110, the surfaces of the electrodes 111 and 121, and the inner wall surface of the reaction vessel 110. Polycrystalline silicon is formed in either case when brass, galvanized iron, or SUS is used as the material of the electrodes 111 and 121.
　図２は、四塩化ケイ素とアルゴンガスとの混合物の超臨界流体状態におけるプラズマ発光スペクトルを示す。図２に示すプラズマ発光スペクトルによれば、ケイ素原子に対応するピーク（２１２．１ｎｍ、２２１．３ｎｍ、２５１．９ｎｍ、２８８．４ｎｍ）が見られる。この中でも、２２１．３ｎｍと２５１．９ｎｍとに、非常に強いピークが検出される。これにより、四塩化ケイ素が原子状に分解していることが分かる。 FIG. 2 shows a plasma emission spectrum in a supercritical fluid state of a mixture of silicon tetrachloride and argon gas. According to the plasma emission spectrum shown in FIG. 2, peaks corresponding to silicon atoms (212.1 nm, 221.3 nm, 251.9 nm, and 288.4 nm) are observed. Among these, very strong peaks are detected at 221.3 nm and 251.9 nm. Thereby, it turns out that silicon tetrachloride has decomposed | disassembled into atomic form.
　図３は、電極１１１，１２１の表面に形成された球状の多結晶シリコンのＳＥＭ像である。図３（ａ）に示すように、電極１１１，１２１の表面に、直径数百ｎｍ～５μｍ程度の球形の多結晶シリコンが生成しているのが分かる。尚、横棒は長さ２５μｍを示す。図３（ｂ）は、図３（ａ）に示す球状の多結晶シリコンの１つの拡大像である。図３（ｂ）下部に示す横棒は、長さ３．５μｍを示す。
　尚、元素分析チャート及び元素マッピングにより球状部分にケイ素が検出されている。
　また、球状の多結晶シリコンのＳＥＭ像は、走査型電子顕微鏡（ＳＥＭ：株式会社日立製作所製ＦＥ－ＳＥＭ　Ｓ－４５００型）により観察した。 FIG. 3 is an SEM image of spherical polycrystalline silicon formed on the surfaces of the electrodes 111 and 121. As shown in FIG. 3A, it can be seen that spherical polycrystalline silicon having a diameter of several hundred nm to 5 μm is formed on the surfaces of the electrodes 111 and 121. In addition, a horizontal bar shows 25 micrometers in length. FIG. 3B is an enlarged image of one of the spherical polycrystalline silicons shown in FIG. The horizontal bar shown in the lower part of FIG. 3B has a length of 3.5 μm.
Silicon is detected in the spherical portion by the elemental analysis chart and elemental mapping.
The SEM image of the spherical polycrystalline silicon was observed with a scanning electron microscope (SEM: FE-SEM S-4500 manufactured by Hitachi, Ltd.).
　図４は、電極１１１，１２１の表面に形成された球状の多結晶シリコンのＥＤＸ（エネルギー分散型蛍光Ｘ線分析装置：Ｅｎｅｒｇｙ　Ｄｉｓｐｅｓｉｖｅ　Ｘ－ｒａｙ　Ｆｌｕｏｒｅｓｃｅｎｃｅ　Ｓｐｅｃｔｒｏｍｅｔｅｒ）マッピング像（図４（ａ））とＥＤＸチャート（図４（ｂ））である。
　図４（ａ）によれば、ＥＤＸマッピング像は、１μｍ～２μｍの分析深さを有し、球状部分が多結晶シリコンであることが分かる。
　また、図４（ｂ）のＥＤＸチャートは、多結晶シリコンが、電極であるＳＵＳ３１６上に生成したことを示している。尚、同時に電極基盤のＳＵＳ３１６の成分である、Ｆｅ、Ｎｉ、Ｃｒも観察されている。 FIG. 4 shows an EDX (Energy Dispersive X-ray Fluorescence Spectrometer) mapping image (FIG. 4A) and EDX of spherical polycrystalline silicon formed on the surfaces of the electrodes 111 and 121. It is a chart (FIG.4 (b)).
According to FIG. 4A, the EDX mapping image has an analysis depth of 1 μm to 2 μm, and it can be seen that the spherical portion is polycrystalline silicon.
Moreover, the EDX chart of FIG.4 (b) has shown that the polycrystal silicon produced | generated on SUS316 which is an electrode. At the same time, Fe, Ni, and Cr, which are components of the electrode substrate SUS316, are also observed.
　図５は、図３に示す球状部分の近傍に形成された膜状の多結晶シリコンのＳＥＭ像である。図５（ａ）に示すように、電極１１１，１２１表面に形成された多結晶シリコンの膜に、多数の割れ目が観察される。横棒は、長さ９０μｍを示す。図５（ｂ）は図５（ａ）のＳＥＭ像の拡大像である。横棒は、長さ１５μｍを示す。図５（ｂ）に示すように、多結晶シリコンの膜表面に僅かに細かい模様が観察される。図５（ｃ）は、さらに拡大したＳＥＭ像である。横棒は、長さ１．５μｍを示す。図５（ｃ）に示すように、多結晶シリコンの膜表面に細かい模様が明確に観察され、緻密な多結晶シリコンが形成されることが分かる。 FIG. 5 is an SEM image of film-like polycrystalline silicon formed in the vicinity of the spherical portion shown in FIG. As shown in FIG. 5A, many cracks are observed in the polycrystalline silicon film formed on the surfaces of the electrodes 111 and 121. The horizontal bar indicates a length of 90 μm. FIG. 5B is an enlarged image of the SEM image of FIG. The horizontal bar indicates a length of 15 μm. As shown in FIG. 5B, a slightly fine pattern is observed on the surface of the polycrystalline silicon film. FIG. 5C is a further enlarged SEM image. The horizontal bar indicates a length of 1.5 μm. As shown in FIG. 5C, a fine pattern is clearly observed on the surface of the polycrystalline silicon film, and it can be seen that dense polycrystalline silicon is formed.
　図６は、電極１１１，１２１表面に形成された多結晶シリコン（ＣＳＣＦＤ）のラマン分光スペクトルを示す（実線）。尚、ラマン分光スペクトルは、レーザラマン分光光度計（日本分光株式会社製ＮＲＳ－１０００）を用いて測定する。励起光の波長は６４７ｎｍであり、分解能は０．５４ｃｍ－１とする。比較として、シリコン単結晶プレート（Ｓｉ　Ｗａｆｅｒ）のラマン分光スペクトル（点線）を併記している。
　図６（ａ）及び図６（ｂ）に示すように、電極１１１，１２１表面に形成された球状部分のラマン分光スペクトルは、シリコン単結晶のラマン分光スペクトルと同様な波数（Ｗａｖｅｎｕｍｂｅｒ／ｃｍ－１）において、同様なシャープなピークが観察されることがわかる。 FIG. 6 shows a Raman spectrum of polycrystalline silicon (CSCFD) formed on the surfaces of the electrodes 111 and 121 (solid line). The Raman spectrum is measured using a laser Raman spectrophotometer (NRS-1000 manufactured by JASCO Corporation). The wavelength of the excitation light is 647 nm, and the resolution is 0.54 cm −1 . For comparison, a Raman spectrum (dotted line) of a silicon single crystal plate (Si Wafer) is also shown.
As shown in FIGS. 6A and 6B, the Raman spectrum of the spherical portion formed on the surfaces of the electrodes 111 and 121 has a wave number (Wavenumber / cm −1) similar to the Raman spectrum of the silicon single crystal. ), A similar sharp peak is observed.
１１０，１２０，１３０…反応容器、１１１，１２１，１１２，１２２，１１３，１２３，…電極、２１…原料貯槽、２２…キャリアガス貯槽、２７…高周波電源、３０…基板、４０…種結晶、５０…析出用部材、５２…坩堝、Ｉ，ＩＩ，ＩＩＩ…製造装置 110, 120, 130 ... reaction vessel, 111, 121, 112, 122, 113, 123, ... electrode, 21 ... raw material storage tank, 22 ... carrier gas storage tank, 27 ... high frequency power supply, 30 ... substrate, 40 ... seed crystal, 50 ... Precipitation member, 52 ... Crucible, I, II, III ... Production equipment

Claims (16)

  1. 　多結晶体の製造方法であって、
    　電極を備えた反応容器中に周期表１４族元素のハロゲン化物を導入し、周期表１４族元素のハロゲン化物の超臨界流体状態を形成する超臨界形成工程と、
    　形成された前記超臨界流体状態にて、前記電極間に電力を印加することによりプラズマ放電を発生させ、周期表１４族元素の多結晶体を生成させるプラズマ放電工程と、
    　を有することを特徴とする多結晶体の製造方法。     A method for producing a polycrystal, comprising:
    A supercritical forming step of introducing a halide of a group 14 element of a periodic table into a reaction vessel equipped with an electrode to form a supercritical fluid state of the group 14 element halide;
    A plasma discharge step of generating a plasma discharge by applying electric power between the electrodes in the formed supercritical fluid state to generate a polycrystal of a group 14 element of the periodic table;
    A method for producing a polycrystalline body, comprising:
  2. 　前記超臨界形成工程は、予め前記反応容器中にキャリアガスを導入し、その後、周期表１４族元素のハロゲン化物を当該反応容器中に導入することを特徴とする請求項１に記載の多結晶体の製造方法。 2. The polycrystal according to claim 1, wherein in the supercritical formation step, a carrier gas is introduced into the reaction vessel in advance, and then a halide of a group 14 element of the periodic table is introduced into the reaction vessel. Body manufacturing method.
  3. 　前記超臨界形成工程は、前記反応容器中にキャリアガス５０ｍｌに対し、周期表１４族元素のハロゲン化物０．１～１００，０００ｍｌを導入することを特徴とする請求項１に記載の多結晶体の製造方法。 The polycrystalline body according to claim 1, wherein in the supercritical formation step, 0.1 to 100,000 ml of a halide of a group 14 element of the periodic table is introduced into the reaction vessel with respect to 50 ml of a carrier gas. Manufacturing method.
  4. 　前記超臨界形成工程は、キャリアガスとしてアルゴン、ヘリウム、ネオン、キセノンから選ばれる少なくとも１種を使用することを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystalline body according to claim 1, wherein the supercritical formation step uses at least one selected from argon, helium, neon, and xenon as a carrier gas.
  5. 　周期表１４族元素が、珪素（Ｓｉ）及びゲルマニウム（Ｇｅ）から選ばれることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystalline body according to claim 1, wherein the group 14 element of the periodic table is selected from silicon (Si) and germanium (Ge).
  6. 　周期表１４族元素のハロゲン化物が、塩化物又は臭化物であることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystal according to claim 1, wherein the halide of the group 14 element of the periodic table is a chloride or bromide.
  7. 　周期表１４族元素のハロゲン化物が、四塩化ケイ素であることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystalline body according to claim 1, wherein the halide of the Group 14 element of the periodic table is silicon tetrachloride.
  8. 　前記反応容器中の圧力が３ＭＰａ以上、当該反応容器中の温度が８０Ｋ以上に保持されることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystal according to claim 1, wherein the pressure in the reaction vessel is maintained at 3 MPa or more and the temperature in the reaction vessel is maintained at 80 K or more.
  9. 　前記プラズマ放電工程において、種結晶上に周期表１４族元素の多結晶体を析出させることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystal according to claim 1, wherein in the plasma discharge step, a polycrystal of a group 14 element of the periodic table is deposited on a seed crystal.
  10. 　前記種結晶の温度を４５０Ｋ以上に保持することを特徴とする請求項９に記載の多結晶体の製造方法。 The method for producing a polycrystalline body according to claim 9, wherein the temperature of the seed crystal is maintained at 450K or higher.
  11. 　前記プラズマ放電工程において、周期表１４族元素の多結晶体を、当該周期表１４族元素の多結晶体の融点より高い温度に保持された析出用部材上に析出させ、且つ、析出した当該周期表１４族元素の多結晶体を融解させることを特徴とする請求項１に記載の多結晶体の製造方法。 In the plasma discharge step, the group 14 element polycrystal is deposited on a deposition member maintained at a temperature higher than the melting point of the group 14 element polycrystal, and the deposited period The method for producing a polycrystal according to claim 1, wherein the polycrystal of the group 14 element is melted.
  12. 　前記析出用部材の温度を１，８００Ｋ以上に保持することを特徴とする請求項１１に記載の多結晶体の製造方法。 The method for producing a polycrystalline body according to claim 11, wherein the temperature of the precipitation member is maintained at 1800K or higher.
  13. 　前記周期表１４族元素の多結晶体が、ポリシリコンであることを特徴とする請求項１に記載の多結晶体の製造方法。 The method for producing a polycrystal according to claim 1, wherein the polycrystal of the group 14 element of the periodic table is polysilicon.
  14. 　ポリシリコンの製造装置であって、
    　内部に導入されたハロゲン化ケイ素化合物の超臨界流体状態を形成するための反応容器本体と、
    　前記反応容器本体の内部に設けられ、プラズマ放電を行うための電極と、
    　前記反応容器本体の内部に設けられ、前記プラズマ放電で分解したシリコンを当該シリコンの融点より高い温度に保持された表面上で析出させ、且つ、析出した当該シリコンを融解させる析出用部材と、
    　前記析出用部材上で融解した前記シリコンを回収する回収部材と、を備える
    ことを特徴とするポリシリコンの製造装置。     A polysilicon manufacturing apparatus,
    A reaction vessel body for forming a supercritical fluid state of the silicon halide compound introduced therein;
    An electrode provided inside the reaction vessel body for performing plasma discharge;
    A deposition member that is provided inside the reaction vessel body, deposits silicon decomposed by the plasma discharge on a surface maintained at a temperature higher than the melting point of the silicon, and melts the deposited silicon;
    And a recovery member for recovering the silicon melted on the deposition member.
  15. 　前記析出用部材は、漏斗状の形状を有し、円錐形の本体部分と、当該本体部分の表面上で析出し且つ融解した前記シリコンを当該本体部分の下方に流下させるように形成された管状部分と、を有することを特徴とする請求項１４に記載のポリシリコンの製造装置。 The deposition member has a funnel-like shape, and is a conical body portion and a tubular shape formed so that the silicon deposited and melted on the surface of the body portion flows down below the body portion. 15. The polysilicon manufacturing apparatus according to claim 14, further comprising: a portion.
  16. 　前記析出用部材は、グラファイトから構成されることを特徴とする請求項１４に記載のポリシリコンの製造装置。
     
     
          15. The polysilicon manufacturing apparatus according to claim 14, wherein the deposition member is made of graphite.


PCT/JP2009/060576 2008-06-13 2009-06-10 Method for producing polycrystalline body and apparatus for producing polysilicon WO2009151070A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-155689 2008-06-13
JP2008155689A JP5284691B2 (en) 2008-06-13 2008-06-13 Method for producing polycrystal of group 14 element of periodic table

Publications (1)

Publication Number Publication Date
WO2009151070A1 true WO2009151070A1 (en) 2009-12-17

Family

ID=41416776

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/060576 WO2009151070A1 (en) 2008-06-13 2009-06-10 Method for producing polycrystalline body and apparatus for producing polysilicon

Country Status (2)

Country Link
JP (1) JP5284691B2 (en)
WO (1) WO2009151070A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5128411B2 (en) * 2008-08-07 2013-01-23 株式会社 シリコンプラス Polysilicon manufacturing apparatus and polysilicon manufacturing method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006054393A1 (en) * 2004-11-22 2006-05-26 Tokyo University Of Agriculture And Technology Method and apparatus for preparing thin film
JP2006249566A (en) * 2005-03-14 2006-09-21 Tokyo Univ Of Agriculture & Technology Method for manufacturing film
JP2006298740A (en) * 2005-04-19 2006-11-02 Kinotech Corp Method for manufacturing silicon

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7128840B2 (en) * 2002-03-26 2006-10-31 Idaho Research Foundation, Inc. Ultrasound enhanced process for extracting metal species in supercritical fluids
JP2006131656A (en) * 2004-11-02 2006-05-25 Daikin Ind Ltd Method for removing fluorine-containing surfactant from polymer composition

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006054393A1 (en) * 2004-11-22 2006-05-26 Tokyo University Of Agriculture And Technology Method and apparatus for preparing thin film
JP2006249566A (en) * 2005-03-14 2006-09-21 Tokyo Univ Of Agriculture & Technology Method for manufacturing film
JP2006298740A (en) * 2005-04-19 2006-11-02 Kinotech Corp Method for manufacturing silicon

Also Published As

Publication number Publication date
JP2009299141A (en) 2009-12-24
JP5284691B2 (en) 2013-09-11

Similar Documents

Publication Publication Date Title
Askari et al. Silicon-based quantum dots: synthesis, surface and composition tuning with atmospheric pressure plasmas
US20140216920A1 (en) Method of Producing Nanoparticles
US20090202415A1 (en) Process for producing high-purity silicon and apparatus
JP2001020072A (en) Method of low temperature synthesis of carbon nanotube using catalyst metal film for decomposition of carbon source gas
JP2003147533A (en) Plasma enhanced chemical vapor deposition apparatus and method of producing carbon nanotube using the same
TW201037107A (en) Apparatus and method of manufacturing polysilicon
JP5128411B2 (en) Polysilicon manufacturing apparatus and polysilicon manufacturing method
WO2009151070A1 (en) Method for producing polycrystalline body and apparatus for producing polysilicon
Mohammad et al. Nanomaterials synthesis routes
JP5712001B2 (en) Polysilicon manufacturing apparatus and method for manufacturing polysilicon
JP5502294B2 (en) Polycrystalline body manufacturing apparatus and polycrystalline body manufacturing method
WO2001048277A1 (en) Method and apparatus for producing single crystal of silicon carbide
JP5180947B2 (en) Cleaning method for a reactor for producing polycrystalline silicon
JP2005314160A (en) Method of synthesizing high density and highly oriented carbon nanotube
JP2011040439A (en) Method of manufacturing optical power generation element
JP5335074B2 (en) Method for producing polycrystalline silicon and reactor for producing polycrystalline silicon
Hamidinezhad et al. Au-Catalyzed Silicon Nanoneedles Synthesized from Pure Silane Gas at Various RF Powers on Silicon Substrate by VHF-PECVD
US7767275B2 (en) Method for synthesizing self-aligned carbon nanomaterials on large area
EP4190748A1 (en) Method of manufacturing high-purity sic crystal
JP5502650B2 (en) Method for manufacturing polysilicon
JP7335551B2 (en) DEVICE FOR FORMING DIAMOND FILM AND METHOD OF FORMING THE SAME
Kawanami et al. Effects of gravity on single-wall carbon nanotubes synthesized by arc in water
JP2006290645A (en) Silicon and its manufacturing method
JP5730423B2 (en) Thermal plasma processing equipment
KR200201953Y1 (en) Diamond thin film formation method by laser ablation combined with high voltage discharge plasma CVD, and diamond bulk fabrication method under the conditions of high temperature and high pressure

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09762500

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09762500

Country of ref document: EP

Kind code of ref document: A1