CN112144107A - Crystal growth furnace and crystal production process - Google Patents

Crystal growth furnace and crystal production process Download PDF

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Publication number
CN112144107A
CN112144107A CN202010948862.2A CN202010948862A CN112144107A CN 112144107 A CN112144107 A CN 112144107A CN 202010948862 A CN202010948862 A CN 202010948862A CN 112144107 A CN112144107 A CN 112144107A
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China
Prior art keywords
crucible
assembly
crystal growth
crystal
heater
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CN202010948862.2A
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Chinese (zh)
Inventor
陈翼
刘奇
黄末
刘林艳
高海棠
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Zhonghuan Leading Xuzhou Semiconductor Materials Co ltd
Zhonghuan Advanced Semiconductor Materials Co Ltd
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Xuzhou Xinjing Semiconductor Technology Co Ltd
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Priority to CN202010948862.2A priority Critical patent/CN112144107A/en
Publication of CN112144107A publication Critical patent/CN112144107A/en
Pending legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/30—Mechanisms for rotating or moving either the melt or the crystal
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/20—Controlling or regulating

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

The invention discloses a crystal growth furnace and a crystal production process, the crystal growth furnace comprises a furnace body, a crucible assembly, a heating assembly and a heat insulation assembly, the crucible assembly comprises a first crucible, a second crucible and a third crucible, a first chamber is suitable for being constructed into a raw material blanking area, a third chamber is suitable for being constructed into a crystal growth area, the heating assembly comprises a first heater and a second heater, the first heater is arranged around the crucible assembly, the second heater is arranged below the crucible assembly, the heat insulation assembly comprises a first heat insulation piece, a second heat insulation piece and a third heat insulation piece, the first heat insulation piece is arranged around the first heater, the second heat insulation piece is arranged at the upper end of the first heat insulation piece and extends inwards to exceed the first heater, so as to surround the crucible assembly, a third heat insulating member is arranged at the upper end of the second heat insulating member and is positioned above the crucible assembly, and the third heat insulating member extends inwards to at least the radial inner side of the first crucible. The crystal growth furnace is beneficial to producing defect-free crystals.

Description

Crystal growth furnace and crystal production process
Technical Field
The invention relates to the technical field of crystal processing equipment, in particular to a crystal growth furnace and a crystal production process.
Background
Currently, single crystal silicon is mainly produced by CZ (czochralski method) and CCZ (continuous czochralski method). In the related technology, research on the technology for producing monocrystalline silicon by CCZ is mainly carried out by correspondingly improving the research on resistivity and a feeding mode (for example, solid feeding, in which the feeding speed is controlled by small particles generally, the crystal growth area and the feeding area are required to be effectively isolated, the influence of impurities in the feeding area on crystal growth is avoided, the control system has low cost and high accuracy, and liquid feeding, in which raw materials are melted by an external melting area and then are put into a crucible by the control system), so that the research on the technology for producing monocrystalline silicon by CCZ is easily limited and is not beneficial to producing defect-free crystals.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a crystal growing furnace, when the crystal growing furnace is used for producing crystals, a crystal growing area has a more stable and uniform temperature gradient, and defect-free crystals can be produced.
The invention also provides a crystal production process.
The crystal growth furnace according to the first aspect of the present invention is a continuous czochralski crystal growth furnace, and includes: a furnace body; the crucible assembly is arranged in the furnace body and comprises a first crucible, a second crucible and a third crucible, a containing space is defined in the first crucible, the top side of the containing space is arranged in an open mode, the second crucible is arranged in the containing space and defines a first cavity together with the first crucible, the third crucible is arranged in the second crucible and defines a second cavity together with the second crucible, a third cavity is defined in the third crucible, a first communication hole is formed in the second crucible to communicate the first cavity with the second cavity, a second communication hole is formed in the third crucible to communicate the second cavity with the third cavity, the first cavity is suitable for being constructed into a raw material blanking area, and the third cavity is suitable for being constructed into a crystal growth area; the heating assembly is arranged in the furnace body and comprises a first heater and a second heater, the first heater is arranged around the crucible assembly, and the second heater is arranged on the lower side of the crucible assembly; thermal-insulated subassembly, thermal-insulated subassembly is located in the furnace body, and include first heat insulating part, second heat insulating part and third heat insulating part, first heat insulating part centers on first heater sets up, the second heat insulating part is established the upper end of first heat insulating part and inwards extend to surpass first heater, in order to center on the crucible subassembly sets up, the third heat insulating part is established the upper end of second heat insulating part and being located the top of crucible subassembly, the third heat insulating part inwards extends to at least the radial inboard of first crucible.
According to the crystal growth furnace, the heat insulation assembly comprises the first heat insulation piece, the second heat insulation piece and the third heat insulation piece, so that the heat insulation assembly is arranged to be matched with the crucible assembly and the heating assembly, the heating assembly is avoided, the heat insulation effect of the heat insulation assembly is improved, a fully-enclosed thermal field structure is convenient to realize, a crystal growth area has a more stable and more uniform temperature gradient when the crystal growth furnace is used for producing crystals, the V/G is convenient to control in a required range, and the defect-free crystals are favorably produced.
In some embodiments, a cooling jacket is further arranged in the furnace body, the cooling jacket is positioned on the right upper side of the third chamber, and the orthographic projection of the cooling jacket is positioned in the outer contour of the orthographic projection of the third crucible on a plane perpendicular to the central axis of the crucible assembly.
In some embodiments, a deflector tube is disposed on the third thermal shield, the deflector tube being located radially outward of the cooling jacket and extending from the third thermal shield toward the third chamber to space the cooling jacket from the top end of the third crucible.
In some embodiments, the top end of the first crucible and the top end of the second crucible are disposed flush and both above the top end of the third crucible, and the third thermal shield extends inwardly to a radially inner side of the second crucible.
In some embodiments, a distance between the outer end of the crucible assembly and the first heater in a radial direction of the crucible assembly is h1, and the h1 satisfies: h1 is more than or equal to 12mm and less than or equal to 20 mm.
In some embodiments, the bottom of the crucible assembly has a mounting projection projecting downward, the second heater is disposed around the mounting projection, a distance between a bottom end of the mounting projection and the second heater in an axial direction of the crucible assembly is h2, and the h2 satisfies: h2 is more than or equal to 0mm and less than or equal to 10 mm.
In some embodiments, a material blocking ring is arranged in the furnace body, the material blocking ring is located between the second crucible and the third crucible in the radial direction of the crucible assembly, the upper end of the material blocking ring is located above the top end of the second crucible in the axial direction of the crucible assembly, and the lower end of the material blocking ring extends to the lower side of the top end of the second crucible.
In some embodiments, the first communication hole has an aperture of d1The diameter of the second communicating hole is d2，d1、d2Satisfies the following conditions: d1＜d2。
In some embodiments, the first communicating hole is formed at the bottom of the second crucible and is arranged adjacent to the R angle of the second crucible, the first communicating hole is multiple, the multiple first communicating holes comprise a first feeding hole and a second feeding hole, and the second feeding hole is positioned above the first feeding hole.
In some embodiments, the first crucible comprises a first body, the second crucible comprises a second body, the third crucible comprises a third body, the first body, the second body and the third body are all formed into a cylindrical structure, the first body, the second body and the third body are arranged in sequence from outside to inside and are coaxially arranged, and the diameter D of the first body1Diameter D of the second body2And a diameter D of the third body3Satisfies the following conditions: dn+1＝Dn*XnWherein n is 1, 2, and X is more than or equal to 60%n≤80％。
In some embodiments, the first crucible includes a crucible bottom wall and crucible side walls extending upwardly from edges of the crucible bottom wall and defining the holding space together with the crucible bottom wall, the second crucible and the third crucible are each formed in a cylindrical configuration, the second crucible is in limit fitting engagement with the crucible bottom wall by a first bayonet configuration, and the third crucible is in limit fitting engagement with the crucible bottom wall by a second bayonet configuration.
In some embodiments, the crucible assembly further comprises: the tray, the tray supports the bottom of first crucible, the top of tray is located the top of first crucible the top of second crucible with the below on the top of third crucible, first crucible includes crucible diapire and crucible lateral wall, the crucible lateral wall certainly the crucible diapire upwards extend and with the crucible diapire prescribes a limit to jointly hold the space, the top of tray is suitable for being located hold the top of liquid level in the space, just the height that the tray exceeds the part of crucible diapire is half of first crucible height.
In some embodiments, the top end of the tray is located above the top end of the first heater, and the distance between the top end of the tray and the first heater in the axial direction of the crucible assembly is h3, and the h3 satisfies: h3 is more than or equal to 30mm and less than or equal to 50 mm.
According to a second aspect of the present invention, there is provided a crystal production process using the crystal growth furnace according to the above first aspect of the present invention, comprising the steps of: s1: material melting: heating the crucible assembly to melt the initial raw material, and after a set time, rotating the crucible assembly at a rotating speed within a set rotating speed section to uniform the internal temperature of the crucible assembly; s2, seeding: immersing a portion of a seed crystal below a level of melt in the crucible assembly; s3, necking: pulling the seed crystal at a speed within a set moving speed section to perform necking; s4, shoulder putting and rotating: controlling the heating power of the heating assembly and the pulling speed of the seed crystal so as to increase the diameter of the crystal to a set diameter; s5, equal-diameter feeding: and in the raw material blanking area, a blanking assembly of the crystal growth furnace adds the added raw material into the raw material blanking area, controls the feeding amount of the blanking assembly to be equal to the crystal forming amount of the crystal, and maintains the liquid level to be constant.
According to the crystal production process, the crucible assembly is arranged to keep rotating speed in the set rotating speed section to rotate in the material melting process so as to uniform the internal temperature of the crucible assembly, so that molten liquid in the crucible assembly is more uniform, and the crystal quality is improved; and the crystal production process is simple, the crystal growth area has more stable and uniform temperature gradient, the V/G is convenient to control in a required range, and the defect-free crystal is favorably produced.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a schematic view of a crystal growth furnace according to one embodiment of the present invention;
FIG. 2 is a schematic view of the crucible assembly shown in FIG. 1;
FIG. 3 is a partial schematic view of the crucible assembly shown in FIG. 2;
FIG. 4 is a graph comparing temperature gradients of crystals at different growth stages in a crystal growth furnace according to one embodiment of the present application;
FIG. 5 is a V/G contrast plot of crystals at various growth stages of a crystal growth furnace according to one embodiment of the present application;
FIG. 6 is a schematic flow diagram of a crystal production process according to one embodiment of the present invention;
FIG. 7 is a schematic flow diagram of a crystal production process according to another embodiment of the invention.
Reference numerals:
200 parts of crystal growing furnace,
A furnace body 101, a main body 101a, an upper cover 101b,
The crucible assembly 102, the holding space 102a, the crucible shaft 1020, the mounting projection 1021,
A first chamber R1, a second chamber R2, a third chamber R3,
A raw material blanking area omega 1, a crystal growth area omega 2,
A first crucible 1, a first body 11, a crucible bottom wall 12, a crucible side wall 13,
A second crucible 2, a first communicating hole 20, a first feeding hole 20a, a second feeding hole 20b, a second body 21,
A third crucible 3, a second communicating hole 30, a third body 31,
A first clamping falcon structure 5, a second clamping falcon structure 6, a tray 7,
Heating unit 103, first heater 1031, second heater 1032,
An insulation assembly 104, a first insulation 1041, a second insulation 1042, a third insulation 1043,
A cooling jacket 105, a guide cylinder 106, a material retaining ring 107,
A magnetic field device 108, a first electrified coil 1081, a second electrified coil 1082,
Blanking subassembly 109, raw materials unloading pipe 1091.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize the applicability of other processes and/or the use of other materials.
Next, a crystal growth furnace 200 according to an embodiment of the first aspect of the present invention is described with reference to the drawings. Wherein the crystal growth furnace 200 is a continuous czochralski crystal growth furnace, that is, the crystal growth furnace 200 is suitable for producing crystals by continuous pulling, that is, CCZ (continuous pulling) is adopted for producing crystals, and the side edge is fed during the crystal pulling process.
As shown in fig. 1 and 2, the crystal growth furnace 200 comprises a furnace body 101 and a crucible assembly 102, the crucible assembly 102 is arranged in the furnace body 101, the crucible assembly 102 comprises a first crucible 1, a second crucible 2 and a third crucible 3, a containing space 102a is defined in the first crucible 1, the top side of the containing space 102a is arranged in an open manner, the containing space 102a can be used for containing a melt of a semiconductor or solar-grade material (such as silicon), and the melt can be formed by heating a solid material; the second crucible 2 is arranged in the containing space 102a, and the second crucible 2 and the first crucible 1 together define a first chamber R1, the first chamber R1 is a part of the containing space 102a, and the first chamber R1 can be located outside the second crucible 2; the third crucible 3 is arranged inside the second crucible 2, and the third crucible 3 and the second crucible 2 together define a second chamber R2, a third chamber R3 is defined inside the third crucible 3, the second chamber R2 and the third chamber R3 both belong to a part of the containing space 102a, and the second chamber R2 may be located outside the third chamber R3.
The second crucible 2 is formed with a first communicating hole 20to communicate the first chamber R1 and the second chamber R2, so that the melt in the first chamber R1 can flow to the second chamber R2 through the first communicating hole 20, or the melt in the second chamber R2 can flow to the first chamber R1 through the first communicating hole 20; the third crucible 3 is formed with a second communication hole 30 to communicate the second chamber R2 and the third chamber R3, and the melt in the second chamber R2 can flow to the third chamber R3 through the second communication hole 30, or the melt in the third chamber R3 can flow to the second chamber R2 through the second communication hole 30.
Wherein the first chamber R1 is adapted to be configured as a raw material blanking region Ω 1, and the third chamber R3 is adapted to be configured as a crystal growth region Ω 2, for example, in the example of fig. 2, top sides of the first chamber R1 and the third chamber R3 may both be open; during use of the crucible assembly 102, charge is introduced into the first chamber R1 and the third chamber R3 is pulled; because the first chamber R1 molten soup needs to flow to the third chamber R3 through the second chamber R2, the second chamber R2 can be suitable for being constructed into a melting zone, so that the molten soup has enough heating time, and the molten soup formed after melting is convenient to provide enough mixing space, so that the uniformity of the molten soup in the third chamber R3 is favorably improved, meanwhile, the phenomenon that incompletely melted materials directly enter the crystal growth zone omega 2 to cause impurities to hit can be prevented, and the high-quality crystals can be conveniently produced. Moreover, the second chamber R2 is arranged to separate the third chamber R3 from the first chamber R1, so that the liquid level is prevented from being disturbed easily in the charging process, the stability of the liquid level in the charging process is guaranteed, the stable growth of crystals is facilitated, and the stable production is guaranteed.
As shown in fig. 1, the crystal growth furnace 200 further includes a heating assembly 103, the heating assembly 103 is disposed in the furnace body 101, and the heating assembly 103 is used for heating the crucible assembly 102 to melt the material. The heating assembly 103 includes a first heater 1031 and a second heater 1032, the first heater 1031 is disposed around the crucible assembly 102, then the first heater 1031 may be located at the radial outer side of the crucible assembly 102, and the first heater 1031 is disposed around the crucible assembly 102 for one full turn or less, for example, the first heater 1031 continuously extends along the circumferential direction of the crucible assembly 102, or the first heater 1031 includes a plurality of sub-heaters spaced along the circumferential direction of the crucible assembly 102, so as to ensure that the first heater 1031 provides sufficient heat; a second heater 1032 is provided at a lower side of the crucible assembly 102 so that the second heater 1032 provides sufficient heat to the bottom of the crucible assembly 102.
As shown in fig. 1, the crystal growth furnace 200 further includes a heat insulation assembly 104, the heat insulation assembly 104 is disposed in the furnace body 101, and the heat insulation assembly 104 includes a first heat insulation member 1041, a second heat insulation member 1042 and a third heat insulation member 1043, the first heat insulation member 1041 is disposed around the first heater 1031, so that the first heat insulation member 1041 may be located at a radial outer side of the first heater 1031, and the first heat insulation member 1041 is disposed around the first heater 1031 for a full turn or less along a circumferential direction of the crucible assembly 102, for example, the first heat insulation member 1041 may be formed into a cylindrical structure, so that the first heat insulation member 1041 may block heat radiation of the heating assembly 103, thereby reducing heat energy loss, facilitating to improve heat energy utilization rate of the crystal growth furnace 200, and ensuring melt rate; the second thermal insulation member 1042 is disposed at the upper end of the first thermal insulation member 1041, and the second thermal insulation member 1042 extends inward beyond the first heater 1031 to surround the crucible assembly 102, so that the second thermal insulation member 1042 is located above the first heater 1031, and the radial inner end of the second thermal insulation member 1042 is located at the radial inner side of the first heater 1031, so that the radial distance between the second thermal insulation member 1042 and the crucible assembly 102 is smaller, which is beneficial to improving the heat preservation and insulation effects of the thermal insulation assembly 104; the third thermal insulator 1043 is disposed at the upper end of the second thermal insulator 1042, the third thermal insulator 1043 is located above the crucible assembly 102, the third thermal insulator 1043 extends inward at least to the radial inner side of the first crucible 1, and the third thermal insulator 1043 covers at least a part of the top side of the first chamber R1, so that the third thermal insulator 1043 can block at least the heat radiation of the melt in the first chamber R1, and further reduce the heat energy loss.
Therefore, the inner wall of the heat insulation assembly 104 is approximately stepped from bottom to top and from outside to inside, the heat insulation assembly 104 is arranged to be matched with the crucible assembly 102 and the heating assembly 103, the avoidance of the heating assembly 103 is realized, the heat insulation effect of the heat insulation assembly 104 is improved, the fully-enclosed thermal field structure is convenient to realize, and the crystal growth region omega 2 has more stable and uniform temperature gradient when the crystal growth furnace 200 produces crystals, namely GnIs uniform and is convenient for maintaining the V/GnWithin the required range, thereby being beneficial to producing the crystal with few defects or even no defects and improving the quality of the crystal. Wherein V is the growth rate of the crystal, GnIs the average axial temperature gradient at the solid-liquid interface.
It should be noted that the direction "inner" refers to a direction close to the central axis of the crucible assembly 102, and the opposite direction is defined as "outer".
Therefore, according to the crystal growth furnace 200 of the embodiment of the present invention, the heat insulation assembly 104 includes the first heat insulation member 1041, the second heat insulation member 1042, and the third heat insulation member 1043, so that the arrangement of the heat insulation assembly 104 matches with the crucible assembly 102 and the heating assembly 103, which not only realizes avoidance of the heating assembly 103, but also improves the heat preservation effect of the heat insulation assembly 104, thereby facilitating realization of a fully enclosed thermal field structure, so that when the crystal growth furnace 200 produces crystals, the crystal growth region Ω 2 has a more stable and uniform temperature gradient, which facilitates control of V/G within a desired range, and is beneficial to production of defect-free crystals.
For example, FIG. 4 shows the temperature gradient G of the crystal growth furnace 200 of the present application during the crystal production process for different lengths of the crystalnWherein "BL" refers to crystal length; as can be seen from FIG. 4, G is the value when the crystal length is less than 850mmnAre uniform, when the crystal length is more than 850mm, the crystal crown shoulder expanding part leaves the top of the cooling jacket 105 of the crystal growth furnace 200 and enters the auxiliary chamber of the crystal growth furnace 200, which causes the heat change at the crystal edge to be obvious, and leads the temperature gradient G at the crystal edge to be obviousnIncreasing that COP defect of defect-free wafer is formed when crystal length is more than 850mm, at which time crystal edge temperature gradient GnThe increase does not affect the growth of defect-free wafers. In addition, due to GnUniform and stable, the crystal growth furnace 200 in the present application can produce crystals with a length of more than 300 mm.
For example, FIG. 5 shows the V/G (i.e., V/G) of the crystal of different lengths during the crystal production process of the crystal growth furnace 200 of the present applicationn) The contrast curve of (1); as can be seen from FIG. 5, due to the temperature gradient GnIs uniform, is convenient to control the V/G within a required range by controlling the growth speed V of the crystal, and avoids the temperature gradient GnThe difference is large, so that the growth speed V is difficult to follow the temperature gradient GnAnd thus it is difficult to control V/G, resulting in more crystal defects. Alternatively, V/G may satisfy 0.0010cm2/min/K≤V/G≤0.0014cm2/min/K。
Alternatively, the insulation assembly 104 may be a piece of insulating material, such as a stiff felt or the like.
In some embodiments, as shown in fig. 1, the lower end of the second thermal insulator 1042 is flush with the top end of the first crucible 1, or the lower end of the second thermal insulator 1042 is located below the top end of the first crucible 1, so that the thermal insulation assembly 104, the crucible assembly 102 and the heating assembly 103 are arranged more compactly under the premise of ensuring the smooth arrangement of the first heater 1031, so as to further improve the heat preservation effect and reduce the volume of the crystal growth furnace 200.
In some embodiments, as shown in fig. 1, a cooling jacket 105 is further disposed in the furnace body 101, and the cooling jacket 105 is located right above the third chamber R3 to achieve crystal solidification and ensure crystal growth; on a plane perpendicular to the central axis of the crucible assembly 102, the orthographic projection of the cooling jacket 105 is located within the outer contour of the orthographic projection of the third crucible 3, and the diameter of the cooling jacket 105 is smaller than the outer contour diameter of the third crucible 3, so that the cooling jacket 105 is closer to the crystal to better cool the crystal.
In the example of fig. 1, the furnace body 101 includes a body 101a and an upper cover 101b, the upper cover 101b is provided on the upper side of the body 101a, the crucible assembly 102 and the heating assembly 103 are both provided inside the body 101a, the upper end of the cooling jacket 105 is connected to the upper cover 101b, and the cooling jacket 105 is provided directly above the crystal growth region Ω 2.
In some embodiments, as shown in fig. 1, the third thermal shield 1043 is provided with a guiding cylinder 106, the guiding cylinder 106 is located at the radial outer side of the cooling jacket 105, and the guiding cylinder 106 extends from the third thermal shield 1043 toward the third chamber R3 to separate the cooling jacket 105 from the top end of the third crucible 3, so that the guiding cylinder 106 can completely separate the cooling jacket 105 from the hot and cold regions of the molten liquid, and the guiding cylinder 106 can reflect the heat of the high-temperature melt back to prevent the crystal growth from being easily radiated by the heat of the high-temperature melt in the crucible assembly 102, thereby ensuring the crystal solidification.
Optionally, in the example of fig. 1, the guide cylinder 106 is a molybdenum piece, compared to the guide cylinder in the prior art that a graphite piece is used, the guide cylinder 106 made of a molybdenum material has a longer service life, and when the crystal growth furnace 200 uses the continuous czochralski method to produce crystals, the production time is longer, so that the structural stability of the guide cylinder 106 is ensured, the graphite is prevented from being easily deformed in the later stage of crystal growth, and space is saved; moreover, in the process of producing the monocrystalline silicon, the condition that graphite forms oxides in silicon vapor to cause poor atmosphere in the furnace body 101 or easily cause crystal impurities to hit can be avoided.
Optionally, the molybdenum guide shell 106 may include multiple molybdenum sheets to facilitate temperature uniformity.
Of course, the invention is not limited to this, and the guide cylinder 106 may further include a casing and a filler, the filler is filled in the casing, the casing is a graphite member, and the filler is a soft felt material member.
In some embodiments, as shown in fig. 1 and 2, the top end of the first crucible 1 and the top end of the second crucible 2 are disposed flush, so that the top end of the first crucible 1 and the top end of the second crucible 2 are substantially located on the same plane, and the top end of the first crucible 1 and the top end of the second crucible 2 are both located above the top end of the third crucible 3, that is, the top end of the third crucible 3 is the lowest in height among the first crucible 1, the second crucible 2 and the third crucible 3, so as to provide sufficient arrangement space for the guide cylinder 106, avoid the third crucible 3 from interfering with the guide cylinder 106, and avoid the third crucible 3 from affecting the airflow flow in the furnace body 101; the third thermal insulation member 1043 extends inward to the radial inner side of the second crucible 2, the third thermal insulation member 1043 can cover the top side of the whole first chamber R1, the heat preservation effect of the thermal insulation assembly 104 is improved, and because the guide cylinder 106 is arranged on the third thermal insulation member 1043, the distance between the third thermal insulation member 1043 and the central axis of the crucible assembly 102 is short, which is beneficial to reducing the size of the guide cylinder 106 in the radial direction of the crucible assembly 102, the occupied space of the guide cylinder 106 is saved, and meanwhile, the guide cylinder 106 is prevented from being large in size and easily interfering with the crucible assembly 102.
In some embodiments, as shown in fig. 1, the inner end of the guide cylinder 106 extends obliquely from top to bottom in a direction toward the cooling jacket 105 in the axial direction of the crucible assembly 102, so that the guide cylinder 106 is formed substantially in a tapered cylinder structure, effectively achieving complete separation of the cooling jacket 105 from the top end of the third crucible 3.
In some embodiments, as shown in fig. 1, the distance between the outer end of the crucible assembly 102 and the first heater 1031 in the radial direction of the crucible assembly 102 is h1, and h1 satisfies: h1 is more than or equal to 12mm and less than or equal to 20 mm. Therefore, the first heater 1031 is prevented from being too far away from the crucible assembly 102, which results in poor heating effect, and the first heater 1031 is also prevented from being too close to the crucible assembly 102, which results in interference.
In some embodiments, as shown in fig. 1, the bottom of the crucible assembly 102 has a downwardly protruding mounting protrusion 1021, the second heater 1032 is disposed around the mounting protrusion 1021, the second heater 1032 is disposed radially outward of the mounting protrusion 1021, and the second heater 1032 is disposed around the mounting protrusion 1021 for one full turn or less; the distance between the bottom end of the mounting projection 1021 and the second heater 1032 in the axial direction of the crucible assembly 102 is h2, and h2 satisfies 0 mm. ltoreq. h 2. ltoreq.10 mm. Therefore, the situation that the second heater 1032 is far away from the crucible assembly 102 to cause poor heating effect is avoided, and the situation that the second heater 1032 is too close to the crucible assembly 102 to cause interference is also avoided. When h2 ≠ 0, the bottom end of the mounting protrusion 1021 is spaced from the second heater 1032 in the axial direction of the crucible assembly 102, and the second heater 1032 may be located above the bottom end of the mounting protrusion 1021 or below the bottom end of the mounting protrusion 1021.
In some embodiments, as shown in fig. 1, a material stop ring 107 is arranged in the furnace body 101, the material stop ring 107 is located between the second crucible 2 and the third crucible 3 in the radial direction of the crucible assembly 102, the upper end of the material stop ring 107 is located above the top end of the second crucible 2 in the axial direction of the crucible assembly 102, and the lower end of the material stop ring 107 extends to below the top end of the second crucible 2. Therefore, the material retaining ring 107 can effectively separate the crystal growth region omega 2 from the raw material blanking region omega 1, and the phenomenon that impurities are easily hit to cause the poor atmosphere of the region close to the crystal growth region omega 2 due to blanking sputtering to cause the crystal to lose a single crystal structure is avoided.
In the example of fig. 1, the guide cylinder 106 is arranged on the third heat insulation member 1043, the baffle ring 107 is arranged on the guide cylinder 106, and the baffle ring 107 is located at the lower side of the guide cylinder 106, which facilitates the arrangement of the baffle ring 107. Wherein, the material blocking ring 107 is a molybdenum member.
In some embodiments, the first communication hole 20 has an aperture diameter d1The diameter of the second communicating hole 30 is d2，d1、d2Satisfies the following conditions: d1＜d2The diameter of the first communication hole 20 is smaller, for example, the diameter of the first communication hole 20 can be smaller than or equal to the diameter of the particles in the first chamber R1, which can be avoidedThe granules directly enter the second chamber R2 without being melted and then enter the third chamber R3 to cause impurities to hit and influence the crystallization rate, thereby being beneficial to ensuring the crystallization rate of crystals; the aperture of the second communicating hole 30 is larger than that of the first communicating hole 20, so that melt retention caused by melt gathering in the second chamber R2 can be avoided, and the melt flow is ensured to be smoother; in addition, the raw material and the dopant are basically melted in the second chamber R2, and the aperture of the second communicating hole 30 is large, so that the influence of solid-liquid interface vibration caused by melt retention on the subsequent crystal pulling process can be avoided.
Wherein, the first communication hole 20 and the second communication hole 30 may be formed as circular holes; of course, when at least one of the first communication hole 20 and the second communication hole 30 is formed as a non-circular hole, the hole diameter of the above-mentioned at least one of the first communication hole 20 and the second communication hole 30 may be understood as an equivalent diameter.
In some embodiments, as shown in FIGS. 2 and 3, the first communicating hole 20 is formed at the bottom of the second crucible 2, and the first communicating hole 20 is disposed adjacent to the R-angle of the second crucible 2. After the particles are melted, because the crucible assembly 102 is cooled and heated from outside and the melt flows downwards from outside to inside under the action of gravity, the first communicating hole 20 is arranged adjacent to the angle R of the second crucible 2, so that the melt can smoothly flow to the second chamber R2 through the first communicating hole 20; moreover, when the particles are not completely melted, the particles become smaller and float upwards under the action of buoyancy, and if the first communicating hole 20 is arranged at the upper part of the second crucible 2, the particles which are not completely melted may flow to the second chamber R2, and then impurities are easily hit, so that the first communicating hole 20 is arranged at the bottom of the second crucible 2, and the particles which are not completely melted can be prevented from entering the third chamber R3 to affect the crystallization rate.
Wherein the angle R of the second crucible 2 can be understood as the angle of the second crucible 2. The position of the R-angle of the crucible is well known to those skilled in the art and will not be described further herein.
As shown in fig. 3, the first communicating hole 2 is formed at the bottom of the second crucible 2, the first communicating hole 20 is plural, the plural first communicating holes 20 include a first feeding hole 20a and a second feeding hole 20b, the second feeding hole 20b is located above the first feeding hole 20a, the first feeding hole 20a can be a main feeding hole, and when the first feeding hole 20a is blocked by adding the second feeding hole 20b above the first feeding hole 20a, the melt in the first chamber R1 can still flow to the second chamber R2 through the second feeding hole 20b, so as to ensure smooth melt flow. Specifically, since the first chamber R1 is suitably configured as the blanking region Ω 1, when the first chamber R1 is charged, the particles have a falling speed such that the particles flow to the bottom of the first chamber R1 to block the first feeding hole 20a, and at this time, the first chamber R1 can still communicate with the second chamber R2 through the second feeding hole 20b, thereby ensuring that the crucible assembly 102 operates normally.
Alternatively, when the first chamber R1 is charged, the charging position may be located at a position of the first chamber R1, and the first charging hole 20a may be located on a side of the second crucible 2 away from the charging position.
The term "plurality" means two or more; "the second feed hole 20b is located above the first feed hole 20 a" merely means that the second feed hole 20b is higher than the first feed hole 20a in horizontal height, and may mean that the second feed hole 20b is located right above the first feed hole 20a, or may mean that the second feed hole 20b is located obliquely above the first feed hole 20a, in other words, in the circumferential direction of the second crucible 2, the relative position between the first feed hole 20a and the second feed hole 20b may be specifically set according to the actual application, and the central angle formed by the position where the first feed hole 20a is disposed and the position where the second feed hole 20b is disposed around the center of the second crucible 2 may range from 0 ° to 360 ° (inclusive).
For example, in the example of fig. 3, the first communication holes 20 are three, the first feed holes 20a are two, the second feed hole 20b is one, and the second feed hole 20b is located above the two first feed holes 20a, and the second feed hole 20b is located between the two first feed holes 20a in the circumferential direction of the second crucible 2.
In some embodiments, as shown in fig. 2, the second communicating hole 30 is formed on the side of the third crucible 3 far from the first communicating hole 20, and for the crucible assembly 102, the first communicating hole 20 and the second communicating hole 30 are respectively located on both sides of the crucible assembly 102 in the radial direction, and the melt flowing to the second chamber R2 through the first communicating hole 20 needs to flow around to the other side of the third crucible 3 to flow to the third chamber R3 through the second communicating hole 30. Therefore, the melt in the containing space 102a flows from the feeding position to the third chamber R3 through a long path, so that the melt can be prevented from flowing fast and easily causing liquid level vibration, and the stability of the liquid level can be ensured.
For example, in the example of FIG. 2, the first chamber R1 and the second chamber R2 are formed in a ring-like configuration, and the second communicating hole 30 is formed on the side of the third crucible 3 in the radial direction away from the first communicating hole 20, so that the melt in the holding space 102a flows in a meandering manner, which is convenient for ensuring a stable liquid level at the time of crystal growth or at the time of charging.
In some embodiments, as shown in fig. 2, the first crucible 1 comprises a first body 11, the second crucible 2 comprises a second body 21, the third crucible 3 comprises a third body 31, the first body 11, the second body 21 and the third body 31 are all formed into a cylindrical structure, the first body 11, the second body 21 and the third body 31 are sequentially arranged from outside to inside, and the first body 11, the second body 21 and the third body 31 are coaxially arranged, so that a central axis of the first body 11, a central axis of the second body 21 and a central axis of the third body 31 are coincidently arranged, and a central axis of the first body 11 can be formed as a central axis of the crucible assembly 102, and the first chamber R1 and the second chamber R2 can be formed into a ring-shaped structure, so that when the crucible assembly 102 is in use, the crucible assembly 102 can rotate around the central axis thereof, and the first chamber R1 rotates around the central axis of the crucible assembly 102, the blanking position of the first chamber R1 may not need to follow the rotation of the crucible assembly 102, facilitating the blanking setting of the crucible assembly 102.
Wherein the diameter D of the first body 111Diameter D of the second body 212And the diameter D of the third body 313Satisfies Dn+1＝Dn*XnWherein n is 1, 2, and X is more than or equal to 60%n80% or less, for example XnMay be 60%, or 70%, or 80%, etc.
Thus, D2＝D1*X1，60％≤X1Less than or equal to 80 percent, and is convenient to ensure the R1 tool of the first chamberThe feeding space is enough, the proper raw material feeding amount is easy to realize, and the melt in the first chamber R1 is convenient to ensure enough flowing space, so that the melt in the first chamber R1 flows to the second chamber R2 through the first communication hole 20; d3＝D2*X2，60％≤X280% or less, under the prerequisite of guaranteeing that third chamber R3 satisfies crystal growth space demand, be convenient for guarantee that second chamber R2 has sufficient space for the fuse-element is more even, and is convenient for guarantee that the fuse-element in the second chamber R2 has sufficient space that flows, makes the fuse-element in the second chamber R2 flow to third chamber R3 through second intercommunicating pore 30. Wherein, X1And X2May or may not be equal.
For example, in the example of fig. 2, the first body 11 is located on top of the first crucible 1, the second body 21 is located on top of the second crucible 2, the third body 31 is located on top of the third crucible 3, X1＝X2When 80%, then D2＝D1*80％、D3＝D 280% of the total weight of the steel. Wherein the diameter D of the third body 313Is larger than the diameter of the crystal, and the ratio of the diameter of the third body 31 to the diameter of the crystal is suitably larger, which is beneficial to making the temperature gradient of the crystal growth region omega 2 more uniform, so as to grow the crystal more easily.
In some embodiments, as shown in fig. 2, the first crucible 1 includes a crucible bottom wall 12 and a crucible side wall 13, the crucible side wall 13 extends upwards from the edge of the crucible bottom wall 12, and the crucible side wall 13 and the crucible bottom wall 12 together define a containing space 102a, the second crucible 2 and the third crucible 3 are both formed into a cylindrical structure, the second crucible 2 is in limit fit with the crucible bottom wall 12 through the first bayonet structure 5, and the third crucible 3 is in limit fit with the crucible bottom wall 12 through the second bayonet structure 6, so as to facilitate the simplification of the structures of the second crucible 2 and the third crucible 3, facilitate the processing, facilitate the assembly between the second crucible 2 and the first crucible 1, and between the third crucible 3 and the first crucible 1, ensure that the crucible assembly 102 is formed into a stable whole, avoid the damage and the movement caused by high crucible rotation, and ensure that the crucible assembly 102 is reliable in use.
Wherein, the concrete structure of first calorie of falcon structure 5 and second calorie of falcon structure 6 can set up according to practical application, only need guarantee that second crucible 2 and 1 assembly of first crucible are reliable, third crucible 3 and 1 assembly of first crucible can reliably.
It should be noted that, in the description of the present application, the "cylindrical structure" is to be understood in a broad sense and is not limited to a cylindrical structure, for example, a polygonal cylindrical structure, nor a cylindrical structure having a constant cross-sectional area, for example, a tapered cylindrical structure.
In some embodiments, as shown in fig. 2, the crucible assembly 102 further comprises a tray 7, wherein the tray 7 is supported at the bottom of the first crucible 1, which is beneficial for improving the bearing capacity of the crucible assembly 102; the top end of the tray 7 is located below the top end of the first crucible 1, the top end of the second crucible 2 and the top end of the third crucible 3, namely, in the first crucible 1, the second crucible 2, the third crucible 3 and the tray 7, the height position of the top end of the tray 7 is lowest, so that on the premise of ensuring the bearing capacity of the crucible assembly 102, the material consumption of the tray 7 can be saved, and the cost is reduced.
Alternatively, in the example of fig. 2, the tray 7 is a graphite piece, and the first crucible 1, the second crucible 2, and the third crucible 3 are all quartz pieces.
As shown in fig. 2, the first crucible 1 includes a crucible bottom wall 12 and a crucible side wall 13, the crucible side wall 13 extends upward from the edge of the crucible bottom wall 12, and the crucible side wall 13 and the crucible bottom wall 12 together define a containing space 102 a. The top of tray 7 is suitable for being located the top of holding the interior liquid level of space 102a, and the tray 7 upwards exceeds the height of the part of crucible bottom wall 12 and is half of the crucible lateral wall 13 height, is convenient for guarantee that crucible assembly 102 stably bears the weight of fuse-element, avoids holding the interior fuse-element of space 102a and appears leaking excessively.
In some embodiments, as shown in FIG. 1, the top end of the tray 7 is located above the top end of the first heater 1031, and the distance between the top end of the tray 7 and the first heater 1031 in the axial direction of the crucible assembly 102 is h3, and h3 satisfies 30mm ≦ h3 ≦ 50 mm. Therefore, the relative height between the first heater 1031 and the crucible assembly 102 is appropriate, so as to ensure the heat energy utilization rate of the first heater 1031, and avoid the problems that the top end of the first heater 1031 is too high and is easy to interfere with the second heat insulation member 1042, and the top end of the first heater 1031 is too low to influence the melt speed.
As shown in fig. 1, the top of the first heater 1031 is adapted not to exceed the liquid level in the crucible assembly 102, and the top of the first heater 1031 is adapted to be flush with the liquid level in the crucible assembly 102, or the top of the first heater 1031 is adapted to be lower than the liquid level in the crucible assembly 102, so that the first heater 1031 can heat the crucible assembly 102 more uniformly, and uniform heating of the melt material is achieved.
In some embodiments, as shown in fig. 1, the crystal growth furnace 200 further comprises a magnetic field device 108, the magnetic field device 108 is disposed outside the furnace body 101, and the magnetic field device 108 is used to generate a magnetic field, which the magnetic field device 108 generates may be used to apply to the melt within the crucible assembly 102. It will be appreciated that the height of the magnetic field means 103 may be specifically set according to the actual requirements.
In some embodiments, as shown in FIG. 1, the magnetic field device 108 includes a first electrical coil 1081 and a second electrical coil 1082, the first electrical coil 1081 is disposed around the furnace body 101, the first electrical coil 1081 is adapted to be positioned above the solid-liquid interface of the melt in the crucible assembly 102, the second electrical coil 1082 is disposed around the furnace body 101, the second electrical coil 1082 is spaced below the first electrical coil 1081, and the second electrical coil 1082 is adapted to be positioned below the solid-liquid interface of the melt in the crucible assembly 102, such that the magnetic field device 108 is simple in structure and easy to implement.
The first electrified coil 1081 and the second electrified coil 1082 have opposite current directions, so that the magnetic field generated by the magnetic field device 108 can be a cusp-shaped magnetic field, and under the action of magnetic lines of force of the cusp-shaped magnetic field, the magnetic lines of force between the first electrified coil 1081 and the second electrified coil 1082 are symmetrically distributed in a "cusp-shaped" manner. For example, during crystal growth, the solid-liquid interface can be located on the symmetrical plane between the first electrified coil 1031 and the second electrified coil 1032, most of the molten liquid is inhibited by the magnetic field, and the generation of turbulence in the molten liquid is effectively reduced.
In some embodiments, as shown in fig. 1, the first electrified coil 1081 and the second electrified coil 1082 are both disposed coaxially with the furnace body 101, such that the central axis of the first electrified coil 1081, the central axis of the second electrified coil 1082 and the central axis of the furnace body 101 coincide; and the first electrified coil 1081 and the second electrified coil 1082 are adapted to be symmetrically disposed about the solid-liquid interface of the melt in the crucible assembly 102, the current levels in the first electrified coil 1081 and the second electrified coil 1082 may be equal, and the number of turns of the first electrified coil 1081 and the second electrified coil 1082 may be equal, so as to simplify the disposition of the magnetic field device 108.
Other configurations and operations of crystal growth furnace 200 according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.
Next, a crystal production process according to an embodiment of the second aspect of the invention is described with reference to the drawings.
The crystal production process using the crystal growth furnace 200 according to the embodiment of the above first aspect of the present invention, as shown in fig. 6 and 7, includes the steps of: s1: material melting: heating the crucible assembly 102 to melt the initial raw material, and after a set time, rotating the crucible assembly 102 at a rotation speed within a set rotation speed section to uniform the temperature inside the crucible assembly 102; s2, seeding: immersing a portion of the seed crystal below the level of the melt in crucible assembly 102; s3, necking: pulling the seed crystal at a speed within a set moving speed section to perform necking; s4, shoulder putting and rotating: controlling the heating power of the heating assembly 103 and the pulling speed of the seed crystal so as to increase the diameter of the crystal to a set diameter; s5, equal-diameter feeding: the equal-diameter growth of the crystal is carried out in the crystal growth region omega 2, in the raw material blanking region omega 1, the blanking component 109 of the crystal growth furnace 200 adds the added raw material into the raw material blanking region omega 1, and the feeding amount of the blanking component 109 is controlled to be equal to the crystal forming amount of the crystal, so as to maintain the liquid level to be constant. In step S5, the additional raw material is added to the raw material feed region Ω 1 while the crystal is being grown in an equal diameter manner, and the crystal is grown in an equal diameter manner while the additional raw material is added.
For example, the initial raw material is loaded into the crucible assembly 102, the total mass of the initial raw material to be added can be calculated according to the liquid level height required by the crucible assembly 102, the crucible assembly 102 is heated to melt the initial raw material in the crucible assembly 102, the initial raw material in the crucible assembly 102 is melted to a certain extent within a set time, and after the initial raw material is melted to a certain extent, the crucible assembly 102 keeps rotating at a rotating speed within a set rotating speed section, so that the temperature inside the crucible assembly 102 is more uniform, which is beneficial to improving the quality of crystals, and meanwhile, the rotation of the crucible assembly 102 is beneficial to making the molten soup in the crucible assembly 102 more uniform; then, about one third of the seed crystal in the axial direction is immersed into the molten liquid in the crucible assembly 102, necking is started when the temperature is stable, and the seed crystal is pulled upwards at the speed within the set moving speed section in the necking process so as to control the diameter of the necking part of the crystal; then, the heating power of the heating assembly 103 and the pulling speed of the seed crystal are controlled to increase the crystal diameter to a set diameter, in the process, the shape of the crystal is mainly controlled, the length-width ratio is used for calculating the geometric shape and the crystal growth angle, and the heating power and the pulling speed are controlled according to the empirical shape to enable the shape of the crystal to reach a required angle, so that the rotary shoulder is put; when the diameter of the crystal is close to the set diameter and equal diameter, the rotary shoulder is placed, the crystal starts to grow in the equal diameter, the feeding component 109 feeds the added raw material to the raw material feeding area omega 1, the crystal is pulled while feeding, continuous crystal pulling production is convenient to achieve, the feeding amount of the feeding component 109 is controlled to be equal to the crystal forming amount of the crystal, and the liquid level is kept constant in the equal diameter process.
Wherein, the rotating speed range of the set rotating speed section can be selected to be 0.2 r/m-3 r/m (including end point values), and the rotating speed of the crucible assembly 102 is lower, so that small crucible rotation of the crucible assembly 102 is realized, the uniform effect of the temperature in the crucible assembly 102 is convenient to ensure, and the aims of avoiding the liquid level fluctuation caused by too high speed and realizing more uniform temperature due to too low speed are fulfilled.
It can be understood that, in step S5, after the crystal is placed on the shoulder, the blanking assembly 109 of the crystal growth furnace 200 is opened, and the crystal grows in an equal diameter, and the feeding amount of the blanking assembly 109 is kept equal to the increased weight of the crystal, for example, for every 1kg of the crystal weight, the blanking assembly 109 needs to feed 1kg of the crystal into the crucible assembly 102, that is, during the equal diameter growth of the crystal, the weight of the molten liquid reduced by each rise of the seed crystal to a certain height needs to be supplemented by the blanking assembly 109 with the same mass of the material, so as to maintain the liquid level stable, ensure the stable growth of the crystal, and facilitate the production of the crystal with larger size.
According to the crystal production process provided by the embodiment of the invention, in the material melting process, the crucible assembly 102 is arranged to keep rotating speed in the set rotating speed section to rotate, so that the internal temperature of the crucible assembly 102 is uniform, the molten liquid in the crucible assembly 102 is more uniform, and the crystal quality is improved; and the crystal production process is simple, the crystal growth region omega 2 has more stable and uniform temperature gradient, the V/G is convenient to control in a required range, and the defect-free crystal is favorably produced.
For example, in the example of FIG. 1, the feed assembly 109 includes a material feed tube 1091, and when the crystal is turned over, the material feed tube 1091 is opened, and the crystal grows in a constant diameter, the amount of additional material fed from the material feed tube 1091 is maintained equal to the weight added to the crystal. It will be appreciated that if it is desired to add dopant to the crucible assembly 102 during the crystal pulling process, the sum of the charge of raw material and the charge of dopant is equal to the amount of crystallized crystal in step S5.
In some embodiments, as shown in fig. 7, prior to step S1, the crystal production process further comprises: the heating assembly 103 and the first heat insulation piece 1041 are sequentially installed in the furnace body 101, the crucible shaft 1020 is lifted to a first height position, the crucible assembly 102 is installed on the crucible shaft 1020, and the crucible shaft 1020 is installed on the furnace body 101 in a lifting manner and is used for driving the crucible assembly 102 to rotate; charging the initial feedstock into crucible assembly 102; the crucible shaft 1020 is lowered to the second height position, the second heat insulation piece 1042, the third heat insulation piece 1043 and the guide cylinder 106 are installed in the furnace body 101, the guide cylinder 106 is used for separating the crystal growth region omega 2, the crystal in the crystal growth region omega 2 is prevented from being easily subjected to the molten liquid in the crucible assembly 102 and the radiation heat of the heating assembly 103, the crystal solidification is guaranteed, meanwhile, the guide cylinder 106 can separate the crystal growth region omega 2 from the raw material blanking region omega 1, and therefore the situation that impurities are easily hit due to poor atmosphere of the crystal growth region omega 2 caused by molten liquid or blanking splashing of the raw material blanking region omega 1 to enable the crystal to lose a single crystal structure is avoided.
Obviously, the first height position is located above the second height position, and then the crucible shaft 1020 is lowered to the second height position, and then the guide cylinder 106 is installed, so that the initial raw material added into the crucible assembly 102 can be prevented from touching the bottom of the guide cylinder 106, the smooth installation of the guide cylinder 106 can be ensured, and the cleanness of the initial raw material in the crucible assembly 102 can be ensured. Alternatively, the first height position is the highest position that the crucible shaft 1020 can reach, and the second height position is the lowest position that the crucible shaft 1020 can reach.
Therefore, the installation and charging sequence of all the components in the furnace body 101 are reasonable, the heat insulation component 104 is installed in a sectional mode, the smooth installation of all the components in the furnace body 101 is facilitated, and the initial raw materials added into the crucible component 102 are prevented from touching other components in the furnace body 101.
In some embodiments, as shown in fig. 1 and 7, the furnace body 101 includes a body 101a and an upper cover 101b, the heating assembly 103, the heat insulation assembly 104, the crucible shaft 1020 and the guide cylinder 106 are all mounted on the body 101a, and before step S1, the crystal production process further includes: after the guide cylinder 106 is installed, the cooling jacket 105 and the blanking assembly 109 of the crystal growth furnace 200 are both installed on the upper cover 101b, the upper cover 101b is fixed on the body 101a, and the interior of the furnace body 101 is vacuumized to better meet the pressure required by crystal growth. Wherein, the cooling jacket 105 is used for cooling the crystal and ensuring the crystal to be solidified into crystal.
Optionally, after the furnace body 101 is vacuumized, the pressure in the furnace body 101 may be maintained at 20torr to 50torr, so as to better meet the requirement of crystal growth.
In some embodiments, prior to step S1, the first R1, the second R2 and the third R3 chamber are filled with starting materials, and the particle diameter of the starting material in the first chamber R1 is larger than the particle diameter of the starting material in the second chamber R2 and the particle diameter of the starting material in the third chamber R3, the particle diameter of the starting material in the first chamber R1 is relatively large in order to secure the charging rate of the first chamber R1, the particle diameter of the starting material in the second chamber R2 and the particle diameter of the starting material in the third chamber R3 are relatively small in order to hold the starting material sufficiently in the second chamber R2 and the third chamber R3, and the gap between the initial raw material particles in the second chamber R2 and the third chamber R3 is small, so that bubbles are prevented from being generated in the melting process, particularly, the phenomenon that the pulling is influenced by the bubbles generated in the third chamber R3 is avoided, and the improvement of the crystal quality is facilitated.
For example, the crystal production process comprises the following steps: s0, charging; charging the initial raw material into the crucible assembly 100; s1, melting; the crucible assembly 100 is heated to melt the initial raw material, and after the set time, the crucible assembly 100 rotates at the rotating speed in the set rotating speed section, so that the internal temperature of the crucible assembly 100 is uniform, the heat insulation assembly 104, the heating assembly 103 and the guide cylinder 106 completely surround the melt, the temperature field of the crystal growth furnace 200 is uniform, the melting temperature is uniform, the raw material and the dopant are uniformly mixed, and the uniform temperature gradient of subsequent crystal growth is ensured. S2, seeding: a portion of the seed crystal is immersed below the level of the melt in crucible assembly 102 and magnetic field device 108 is turned on. S3: necking: and pulling the seed crystal at a speed within the set moving speed section to neck the seed crystal and remove dislocation. In this case, the moving speed range may be set to 2mm/min to 3mm/min (inclusive), so as to ensure smooth necking. S4: placing a rotary shoulder: controlling the heating power and the pulling speed of the seed crystal to increase the diameter of the crystal to a set diameter; s5: and (3) constant-diameter feeding: the equal-diameter growth of the crystal is carried out in the crystal growth region omega 2, in the raw material blanking region omega 1, the raw material blanking pipe adds the added raw material into the raw material blanking region omega 1 of the crucible assembly 102, the feeding amount of the blanking assembly is controlled to be equal to the crystal forming amount of the crystal, and the liquid level is kept constant. Through setting up the material retaining ring 107 at draft tube 106, avoided the unloading splash to cause the regional atmosphere that is close to crystal growth district omega 2 not good to lead to the impurity to hit easily and make the crystal lose single crystal structure on the one hand, the thermal field design of thermal-insulated subassembly 104, heating element 103, draft tube 106, the feeding zone, the raw materials melts fast, through the melting zone, flows into crystal growth district omega 2, the temperature gradient of crystal growth district omega 2 is even for flawless crystal grows smoothly.
In the description of the present invention, it is to be understood that the terms "central," "upper," "lower," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for the purpose of convenience and simplicity of description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (14)

1. A crystal growth furnace (200), characterized in that the crystal growth furnace (200) is a continuous czochralski crystal growth furnace and comprises:
a furnace body (101);
crucible assembly (102), crucible assembly (102) is located in furnace body (101), and includes first crucible (1), second crucible (2) and third crucible (3), it holds space (102a) to inject in first crucible (1), hold the open setting in top side of space (102a), establish second crucible (2) hold in space (102a) and with first crucible (1) prescribe a limit to first cavity (R1) jointly, establish third crucible (3) in second crucible (2) and with second crucible (2) prescribe a limit to second cavity (R2) jointly, prescribe a limit to third cavity (R3) in third crucible (3), be formed with first intercommunication hole (20) on second crucible (2) in order to communicate first cavity (R1) with second cavity (R2), be formed with second intercommunication hole (30) on third crucible (3) in order to communicate second cavity (R2) with third crucible (R2) A chamber (R3), the first chamber (R1) being adapted to be configured as a raw material blanking region (Ω 1), the third chamber (R3) being adapted to be configured as a crystal growth region (Ω 2);
a heating assembly (103), wherein the heating assembly (103) is arranged in the furnace body (101) and comprises a first heater (1031) and a second heater (1032), the first heater (1031) is arranged around the crucible assembly (102), and the second heater (1032) is arranged at the lower side of the crucible assembly (102);
heat insulation assembly (104), heat insulation assembly (104) is located in furnace body (101), and include first heat insulating part (1041), second heat insulating part (1042) and third heat insulating part (1043), first heat insulating part (1041) centers on first heater (1031) sets up, second heat insulating part (1042) is established the upper end of first heat insulating part (1041) and inwards extends to surpass first heater (1031), in order to surround crucible assembly (102) sets up, third heat insulating part (1043) is established the upper end of second heat insulating part (1042) and is located the top of crucible assembly (102), third heat insulating part (1043) inwards extends to at least first crucible (1) is radial inboard.
2. The crystal growth furnace (200) according to claim 1, characterized in that a cooling jacket (105) is further provided in the furnace body (101), the cooling jacket (105) is located directly above the third chamber (R3), and an orthographic projection of the cooling jacket (105) is located within an outer contour of an orthographic projection of the third crucible (3) on a plane perpendicular to the central axis of the crucible assembly (102).
3. The crystal growth furnace (200) according to claim 2, characterized in that a guide cylinder (106) is provided on the third thermal shield (1043), the guide cylinder (106) being located radially outside the cooling jacket (105) and extending from the third thermal shield (1043) towards the third chamber (R3) to separate the cooling jacket (105) from the top end of the third crucible (3).
4. The crystal growth furnace (200) according to claim 3, characterized in that the top end of the first crucible (1) and the top end of the second crucible (2) are arranged flush and both located above the top end of the third crucible (3), the third thermal shield (1043) extending inwards to the radially inner side of the second crucible (2).
5. The crystal growth furnace (200) according to claim 1, characterized in that, in a radial direction of the crucible assembly (102), a distance between an outer end of the crucible assembly (102) and the first heater (1031) is h1, the h1 satisfies: h1 is more than or equal to 12mm and less than or equal to 20 mm.
6. The crystal growth furnace (200) according to claim 1, wherein the bottom of the crucible assembly (102) has a mounting protrusion (1021) protruding downward, the second heater (1032) is disposed around the mounting protrusion (1021), a distance h2 between a bottom end of the mounting protrusion (1021) and the second heater (1032) in an axial direction of the crucible assembly (102), and the h2 satisfies: h2 is more than or equal to 0mm and less than or equal to 10 mm.
7. The crystal growth furnace (200) according to any of claims 1-6, characterized in that a material-stopping ring (107) is arranged in the furnace body (101), the material-stopping ring (107) is located between the second crucible (2) and the third crucible (3) in the radial direction of the crucible assembly (102), the upper end of the material-stopping ring (107) is located above the top end of the second crucible (2) in the axial direction of the crucible assembly (102), and the lower end of the material-stopping ring (107) extends to below the top end of the second crucible (2).
8. The crystal growth furnace (200) according to claim 1, characterized in that the first communication hole (20) has a hole diameter d1The diameter of the second communication hole (30) is d2，d1、d2Satisfies the following conditions: d1＜d2。
9. The crystal growth furnace (200) according to claim 1, characterized in that the first communication hole (20) is formed at the bottom of the second crucible (2) and is arranged adjacent to the R-angle of the second crucible (2),
the first communication holes (20) are multiple, the multiple first communication holes (20) comprise a first feeding hole (20a) and a second feeding hole (20b), and the second feeding hole (20b) is positioned above the first feeding hole (20 a).
10. Crystal growth furnace (200) according to claim 1, characterized in that said first crucible (1) comprises a first body (11), said second crucible (2) comprises a second body (21), said third crucible (3) comprises a third body (31), said first body (11), said second body (21) and said third body (31) are each formed as a cylindrical structure, said first body (11), said second body (21) and said third body (31) are arranged in sequence from outside to inside and coaxially, said first body (11) has a diameter D1Diameter D of the second body (21)2And the diameter D of the third body (31)3Satisfies the following conditions: dn+1＝Dn*XnWherein n is 1, 2, and X is more than or equal to 60%n≤80％。
11. The crystal growth furnace (200) according to claim 1, characterized in that the first crucible (1) comprises a crucible bottom wall (12) and crucible side walls (13), the crucible side walls (13) extending upwardly from the edge of the crucible bottom wall (12) and defining together with the crucible bottom wall (12) the holding space (102a), the second crucible (2) and the third crucible (3) each being formed as a cylindrical structure, the second crucible (2) being in limit-fitting engagement with the crucible bottom wall (12) by a first bayonet joint structure (5), the third crucible (3) being in limit-fitting engagement with the crucible bottom wall (12) by a second bayonet joint structure (6).
12. The crystal growth furnace (200) of claim 1, wherein the crucible assembly (102) further comprises:
a tray (7), wherein the tray (7) is supported at the bottom of the first crucible (1), the top end of the tray (7) is positioned below the top end of the first crucible (1), the top end of the second crucible (2) and the top end of the third crucible (3), the first crucible (1) comprises a crucible bottom wall (12) and a crucible side wall (13), the crucible side wall (13) extends upwards from the crucible bottom wall (12) and defines the containing space (102a) together with the crucible bottom wall (12),
the top end of the tray (7) is suitable for being positioned above the liquid level in the containing space (102a), and the height of the part of the tray (7) exceeding the bottom wall (12) of the crucible is half of the height of the first crucible (1).
13. The crystal growth furnace (200) according to claim 12, characterized in that the top end of the tray (7) is located above the top end of the first heater (1031), and the distance between the top end of the tray (7) and the first heater (1031) in the axial direction of the crucible assembly (102) is h3, the h3 satisfies: h3 is more than or equal to 30mm and less than or equal to 50 mm.
14. A crystal production process, characterized by using a crystal growth furnace (200) according to any one of claims 1-13, and comprising the steps of:
s1: material melting: heating the crucible assembly (102) to melt the initial raw material, and after a set time, rotating the crucible assembly (102) at a rotating speed within a set rotating speed section to homogenize the temperature inside the crucible assembly (102);
s2, seeding: immersing a portion of a seed crystal below a level of melt within the crucible assembly (102);
s3, necking: pulling the seed crystal at a speed within a set moving speed section to perform necking;
s4, shoulder putting and rotating: controlling the heating power of the heating assembly (103) and the pulling speed of the seed crystal so as to increase the diameter of the crystal to a set diameter;
s5, equal-diameter feeding: and (2) performing equal-diameter growth of crystals in the crystal growth region (omega 2), adding a raw material to be added into the raw material blanking region (omega 1) by a blanking assembly (109) of the crystal growth furnace (200) in the raw material blanking region (omega 1), controlling the feeding amount of the blanking assembly (109) to be equal to the crystallization amount of the crystals, and maintaining the liquid level to be constant.
CN202010948862.2A 2020-09-10 2020-09-10 Crystal growth furnace and crystal production process Pending CN112144107A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114108094A (en) * 2021-11-30 2022-03-01 江苏集芯半导体硅材料研究院有限公司 Silicon carbide crystal growing device
TWI836869B (en) * 2022-01-29 2024-03-21 中國大陸商中環領先半導體科技股份有限公司 Cooling device and control method thereof, crystal growth equipment

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6476992A (en) * 1987-06-08 1989-03-23 Mitsubishi Metal Corp Apparatus for growing single crystal
CN1056136A (en) * 1990-04-27 1991-11-13 日本钢管株式会社 Silicon single crystal manufacturing apparatus
CN104903496A (en) * 2012-11-29 2015-09-09 索拉克斯有限公司 Heat shield for improved continuous czochralski process
CN105247114A (en) * 2013-03-14 2016-01-13 爱迪生太阳能公司 Czochralski crucible for controlling oxygen and related methods
CN106574391A (en) * 2014-07-25 2017-04-19 爱迪生太阳能公司 Crystal growing systems and methods including a passive heater

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6476992A (en) * 1987-06-08 1989-03-23 Mitsubishi Metal Corp Apparatus for growing single crystal
CN1056136A (en) * 1990-04-27 1991-11-13 日本钢管株式会社 Silicon single crystal manufacturing apparatus
CN104903496A (en) * 2012-11-29 2015-09-09 索拉克斯有限公司 Heat shield for improved continuous czochralski process
CN105247114A (en) * 2013-03-14 2016-01-13 爱迪生太阳能公司 Czochralski crucible for controlling oxygen and related methods
CN106574391A (en) * 2014-07-25 2017-04-19 爱迪生太阳能公司 Crystal growing systems and methods including a passive heater

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
沈文忠主编: "《太阳能光伏技术与应用》", 31 October 2013, 上海交通大学出版社 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114108094A (en) * 2021-11-30 2022-03-01 江苏集芯半导体硅材料研究院有限公司 Silicon carbide crystal growing device
TWI836869B (en) * 2022-01-29 2024-03-21 中國大陸商中環領先半導體科技股份有限公司 Cooling device and control method thereof, crystal growth equipment

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