GB2322734A - Semiconductor device and a method of manufacturing the same - Google Patents
Semiconductor device and a method of manufacturing the same Download PDFInfo
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- GB2322734A GB2322734A GB9704056A GB9704056A GB2322734A GB 2322734 A GB2322734 A GB 2322734A GB 9704056 A GB9704056 A GB 9704056A GB 9704056 A GB9704056 A GB 9704056A GB 2322734 A GB2322734 A GB 2322734A
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- Prior art keywords
- bpsg
- semiconductor device
- bpsg film
- film
- hydrophobic
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- 239000004065 semiconductor Substances 0.000 title claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 67
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 39
- 229910052796 boron Inorganic materials 0.000 claims abstract description 28
- 238000005204 segregation Methods 0.000 claims abstract description 25
- 239000011229 interlayer Substances 0.000 claims abstract description 22
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 20
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 13
- 239000010410 layer Substances 0.000 claims description 26
- 229910052698 phosphorus Inorganic materials 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 13
- 239000000758 substrate Substances 0.000 claims description 13
- 239000004215 Carbon black (E152) Substances 0.000 claims description 12
- 229930195733 hydrocarbon Natural products 0.000 claims description 12
- 150000002430 hydrocarbons Chemical class 0.000 claims description 12
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 10
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical group [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 9
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 9
- 125000000962 organic group Chemical group 0.000 claims description 9
- -1 ethoxyl group Chemical group 0.000 claims description 5
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 4
- 125000003545 alkoxy group Chemical group 0.000 claims description 4
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 claims description 4
- 239000005368 silicate glass Substances 0.000 claims description 4
- GDFCWFBWQUEQIJ-UHFFFAOYSA-N [B].[P] Chemical compound [B].[P] GDFCWFBWQUEQIJ-UHFFFAOYSA-N 0.000 claims description 3
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical compound [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 claims description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 3
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 claims 1
- 230000008569 process Effects 0.000 abstract description 20
- 235000019441 ethanol Nutrition 0.000 abstract description 11
- 125000004437 phosphorous atom Chemical group 0.000 abstract description 3
- 239000005380 borophosphosilicate glass Substances 0.000 abstract 6
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 24
- 125000004429 atom Chemical group 0.000 description 13
- 239000012535 impurity Substances 0.000 description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 9
- 229920005591 polysilicon Polymers 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 229910052814 silicon oxide Inorganic materials 0.000 description 6
- 235000012431 wafers Nutrition 0.000 description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 239000011574 phosphorus Substances 0.000 description 5
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- NBBJYMSMWIIQGU-UHFFFAOYSA-N Propionic aldehyde Chemical compound CCC=O NBBJYMSMWIIQGU-UHFFFAOYSA-N 0.000 description 2
- 150000001299 aldehydes Chemical class 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- ZXEKIIBDNHEJCQ-UHFFFAOYSA-N isobutanol Chemical compound CC(C)CO ZXEKIIBDNHEJCQ-UHFFFAOYSA-N 0.000 description 2
- 238000001459 lithography Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 description 1
- DCERHCFNWRGHLK-UHFFFAOYSA-N C[Si](C)C Chemical compound C[Si](C)C DCERHCFNWRGHLK-UHFFFAOYSA-N 0.000 description 1
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- ZTQSAGDEMFDKMZ-UHFFFAOYSA-N butyric aldehyde Natural products CCCC=O ZTQSAGDEMFDKMZ-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229930003836 cresol Natural products 0.000 description 1
- POLCUAVZOMRGSN-UHFFFAOYSA-N dipropyl ether Chemical compound CCCOCCC POLCUAVZOMRGSN-UHFFFAOYSA-N 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- UQEAIHBTYFGYIE-UHFFFAOYSA-N hexamethyldisiloxane Chemical compound C[Si](C)(C)O[Si](C)(C)C UQEAIHBTYFGYIE-UHFFFAOYSA-N 0.000 description 1
- 229940073561 hexamethyldisiloxane Drugs 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 230000005660 hydrophilic surface Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229940035429 isobutyl alcohol Drugs 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000004518 low pressure chemical vapour deposition Methods 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- DOTMOQHOJINYBL-UHFFFAOYSA-N molecular nitrogen;molecular oxygen Chemical compound N#N.O=O DOTMOQHOJINYBL-UHFFFAOYSA-N 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000010183 spectrum analysis Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000009279 wet oxidation reaction Methods 0.000 description 1
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
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
-
- 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
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/31051—Planarisation of the insulating layers
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
- Formation Of Insulating Films (AREA)
Abstract
In a method of manufacturing a semiconductor device, a BPSG film is formed as an interlayer insulating film. A process is then applied to the BPSG film for making a surface of the BPSG film hydrophobic. This process comprises supplying an organic compound gas such as ethyl alcohol gas, and a gas containing O 2 and O 3 and is carried out, at a temperature equal to or higher than that used in BPSG film formation. Then, the BPSG film is reflowed such that the BPSG film surface is flattened. Segregation of B and P atoms is thereby prevented.
Description
SEMICONDUCTOR DEVICE AND A METHOD OF MANUFACTURING THE SAME The present invention relates to a semiconductor device and a method of nn & actur same, and more particularly to a semiconductor device and a method of manufacturing the same in which an interlayer insulating film of the semiconductor device is flattened.
As the integration density of a semiconductor device is increased, the three dimensional structure of circuits of the semiconductor device becomes further complicated. On the other hand, the needfrhighprecision flatness of an interlayer insulating film which is formed on a circuit pattern has has mm n severe for the necessity of lithography technique in recent years. A conventional method of flattening the interlayer insulating film which is most generally performed is a method in which the interlayer insulating film is formed using a silicon oxide film to which the impurities such as phosphorus (P) and boron (B) are added (boron phosphorus silicate glass, to be referred to as a "BPSG film" hereinafter), and heat treatment is performed at a temperature equal to or higher than the melting point of the BPSG film to flow the BPSG film, so that the surface of the BPSG film is flattened using the surface tension (this method is referred to as a "reflow method" hereinafter). The flattening of the interlayer insulating film can be most simply performed.
Also, in the above conventional flattening method, the reflow method is performed using the single BPSG layer.
However, there is proposed another conventional method in which after the BPSG film is formed, a silicon oxide film such as phosphorus silicate glass film (hereinafter, to be referred to as a "PSG film") is formed on the BPSG film and then the reflow method is performed, for the purpose of preventing segregation of impurities from the BPSG film surface (see Japanese Laid Open Patent Disclosure (JP-A-Showa 61-237448)). Also, for the purpose of preventing the impurity segregation which occurs in the cooling of the
BPSG film, there is also proposed a method in which heat treatment for the reflow is executed in a low pressure CvD apparatus, and then a silicon oxide film or a silicon nitride film is formed on the BPSG film within the same apparatus before the cooling after the execution of reflow (see
Japanese Laid Open Patent Disclosure (JP-A-Heisei 4-129223)).
Here, the impurity segregation means the phenomenon in which
P or B atoms which are added to the BPSG film segregate on the BPSG film surface to have the thickness of several Am or tens of Aim. As the result of the impurity segregation, the yield of the.semiconductor device is greatly influenced.
Hereinafter, the conventional methods of flattening the interlayer insulating film will be described with reference to Figs. 1A and 1B.
- First, as shown in Fig. 1A, the BPSG film 4 is grown as an interlayer insulating film on a semiconductor substrate 1 on which a gate oxide film 2 and a circuit pattern 3 composed of a polysilicon film and so on are already formed, using a suitable CvD method. The BPSG film 4 has a desired film thickness and added with P atoms of the concentration of about 3 to 6 mol% and B atoms of the concentration of about 8 to 13 mol%. Then, a silicon oxide film 5 of PSG and so on is deposited to have the thickness of 0.01 to 0.02 Am as a segregation preventing film against the P and B atoms using a suitable CvD method.
Next, as shown in Fig. IB, heat treatment is performed in nitrogen ambience for 5 to 30 minutes at about 900 "C such that the BPSG film 4 and the PSG film 5 are flattened.
Besides, there is still another method in which concentration gradients of P and B are provided in a depth direction of the BPSG film such that the concentrations of P and B are lower nearer to the surface of the BPSG film. That is, in this method, the surface concentrations of P and B are decreased such that a segregation margin is extended (see
Japanese Laid Open Patent Disclosure (JP-A-Heisei 5-275424)).
Further, there is proposed a method in which a polysilicon film has been previously formed to prevent oxidation by 02, which invades into the semiconductor substrate and diffusion layers, using not a reflow method in the nitrogen ambience which method is the most popular at present but a wet oxidation method in hydrogen - oxygen ambience (H2 - 02) or a nitrogen - oxygen ambience (N2 - 02). Then, the polysilicon film is oxidized to provide flattening and oxidation resistance in the reflow process (see Japanese Laid Open
Patent Disclosure (JP-A-Heisei 3-135025)).
There are the following problems in these conventional methods of flattening the interlayer insulating film. First, in the method in which the segregation preventing film is grown on the BPSG film surface before the reflow, or, the surface concentrations of P and B atoms are decreased in the BPSG film to form a cap layer, this segregation preventing film prevents flattening of the BPSG film. That is, since the diffusion of P and B atoms into the segregation preventing film is not sufficient during the reflow process, the flattening becomes incomplete, compared to the BPSG film which does not have the segregation preventing film. In addition, in a case where the film thickness of the segregation preventing film is not constant between wafers and between portions of each wafer, the flattening shape of the BPSG film is quite different from between the wafers and between the portions of each wafer, of course.
Second, in the method in which the segregation preventing film is formed in the same CVD apparatus after the reflow process, it is necessary to change a furnace temperature profile from an approximately flat profile for the reflow process to a tilt profile for a liquid phase chemical vapor deposition (LPCVD). Therefore, the process of growing the film requires a tine period 3 to 4 ts longar than that of the simple reflow process. As a result of this, it is seen that the productivity is reduced. In addition, it could be understood that because the thermal history becomes long, the method can not be applied to semiconductor device having a shallow diffusion layer which is required in advanced semiconductor devices in recent years.
Third, in case of the method in which the concentration gradients of P and B are provided in the depth direction of the BPSG film such that the concentrations of P and B become lower at a portion nearer to the BPSG film surface, the concentration gradients must be always kept constant. However, it is impossible to analyze the concentration in the depth direction by a fluorescent X-ray analysis method and a Fourier transform infrared-rays spectrum analysis method (FT-IR) which are generally used
Accordingly, a complicated and expensive method such as a primary ion mass analysis (SIMS) is required for the concentration gradient .anaiysis. In addition, because it is necessary to set a film forming condition for each of various film thicknesses to be produced, it is impossible to manage the process control in the mass production step.
Fourth, in case of the method of performing the reflow in oxygen containing ambience as in steam processing
(H2 - Out), oxidizing species reach the substrate through the silicon oxide film of BPSG which is formed as the interlayer insulating film. Therefore, because the substrate is oxidized, the film thickness of the gate oxide film is increased. As a result, the device characteristics are degraded. For this reason, it is popular in the advanced semiconductor device of recent years that the reflow process is performed in nitrogen ambience. Also, in the conventional method, the polysilicon film is used as the oxidation resistance film of the substrate. Therefore, when a contact is formed, if a part of the polysilicon film is left in a contact hole without being oxidized, a contact short-circuited fault is caused. Therefore, the polysilicon film must be completely oxidized. However, since the oxidation is performed through the BPSG film which has been formed on the polysilicon film, the oxidation speed greatly depends on the film thickness of the BPSG film. For this reason, it is required that the polysilicon film has a completely uniform thickness between wafers and between portions on the same wafer surface in addition to the uniform
BPSG film thickness. However, this is impractical.
Therefore, an object of at least the preferred exSments of the present invention is to provide a semiconductor device and a method of manufacturing the same, in which impurity segregation from an interlayer insulating film can be prevented, and further the flatness of the interlayer insulating film after a reflow process is improved.
Accordingly, in a first aspect the present invention provides a method of manufacturing a semiconductor device, comprising the steps of:
forming a boron phosphorus silicate glass (BPSG) layer;
performing a hydrophobic processing to make a surface of said BPSG layer hydrophobic; and
subsequently heating said BPSG layer to flatten said surface of said BPSG layer.
In a preferred embodiment of this aspect of the present invention, a method of manufacturing a semiconductor device comprises the steps of:
forming a BPSG film as an interlayer insulating film;
performing a hydrophobic processing for making a surface of the BPSG film hydrophobic after the BPSG film is formed; and
reflowing the BPSG film such that the BPSG film surface is flattened, after the hydrophobic processing.
When total concentration of phosphorous and boron atoms in the BPSG film are lower than a segregation limit total concentration of P and B atoms respectively, the hydrophobic processing is performed at a same temperature as in the step of forming a BPSG film. At this time, an organic compound gas of hydrocarbon and a gas composed of O2 and 03 with 03 concentration of 90 to 120 g/l are supplied.
The reflow of the BPSG film is performed at a temperature equal to or higher than 850"C. On the other hand, when total concentration of phosphorous and boron atoms in the BPSG film are equal to or higher than a segregation limit total concentration of P and B atoms respectively, the hydrophobic processing is performed at a temperature higher than in the step of forming a BPSG film, e.g., at a temperature of 650 to 700"C. At this time, an organic compound gas of hydrocarbon and a gas composed of O2 and 03 with 03 concentration of 250 to 350 g/l are supplied. The reflow of the BPSG film is performed at a temperature of 800 to 850 "C In another preferred odint of this first aspect of the present invention, a method of manufacturing a semiconductor device
comprises the steps of:
forming an interlayer insulating film;
performing a hydrophobic processing to the interlayer insulating film using an organic compound gas to substitute an organic group containing hydrocarbon for a hydroxyl group on the BPSG film surface; and
reflowing the interlayer insulating film such that the BPSG film surface is flattened, after the hydrophobic processing.
The organic compound gas is selected from the group consisting of alcohol, phenol, ether, aldehyde and hexaalkyl disiloxane. When the organic compound gas is alcohol, the alcohol is desirably a normal chain hydrocarbon alcohol, and more desirably methyl alcohol. It is desirable that the organic group includes hydrocarbon. Also, the organic group is desirably an alkoxyl group, and more desirably ethoxyl group.
In a second aspect of the present invention, a semiconductor device comprises a conductive circuit pattern formed on a semiconductor substrate, and an insulating layer formed on the substrate including the circuit pattern, and having a hydrophobic layer on a surface thereof,
Preferred features of the present invention will now be described, purely by way of example only, with reference to the accompanying drawings, in which:
Figs. 1A and 1B are cross sectional views of a conventional semiconductor device to describe a method of manufacturing the conventional semiconductor device;
Figs. 2A and 2B are cross sectional views which are used for describing a semiconductor device according to the first embodiment of the present invention; and
Figs. 3A and 3B are expanded schematic diagrams indicative of the molecule structure of a portion pointed by a circle A in Fig. 2A, before hydrophobic processing and after the hydrophobic processing, respectively.
First, the semiconductor device according to the first embodiment of the present invention will be described.
Figs. 2A and 2B are cross sectional views of the semiconductor device in the first embodiment in the manufacturing process of the same. Figs. 3A and 3B are expanded schematic diagrams indicative of the molecule structure of a portion indicated by a circle A in Fig. 2A, before hydrophobic processing and after the hydrophobic processing, respectively.
First, as shown in Fig. 2A, after a gate oxide film 2 and a circuit pattern 3 composed of polysilicon and so on are formed on a semiconductor substrate 1, a BPSG film 4 having a desired film thickness is grown by a CVt method which uses as a process gas a gas of a tetraethylorthosilicate (Si(OCH2CH3)4, to be referred to as "TEOS", hereinafter) ozonic gas (O) system. To the BPSG film, phosphorus atoms of the concentration of 3 - 6 mol% and boron atoms of the concentration of 8 - 13 mol% are added. In this case, as shown in Fig. 3A, the surface of the BPSG film has the hydrophilic surface in which each molecule is terminated with the -OH group, when the BPSG film is formed at a temperature of 400 - 550 "C. The temperature is continuously maintained and ethyl alcohol gas (C2HsOH) as an organic gas containing hydrocarbon is supplied at the rate of 30 - 100 sccm (cm3/minute) and (02 + 031 gas is also supplied at the rate as much as 3.0 - 10.0 SLM with O3 concentration of 90 - 120 g/l.
As a result, the hydroxyl group (-OH) which exists on the
BPSG film surface is substituted by an ethoxyl group (-OC2Hs). That is, the BPSG film surface is terminated by the organic group by this surface hydrophobic processing so that the BPSG film surface is made hydrophobic, as shown in
Fig. 3B.
More particularly, in case of the BPSG film which is formed by a CVD method, the oxidation reaction by the process gas becomes incomplete as the growth rate becomes fast.
Therefore, the BPSG film contains a lot of -OH groups on the surface. Especially, P and B ions are not combined with Si through oxygen atom but with the -OH groups and the BPSG film surface is hydrophilic. For this reason, the BPSG film surface is easily hydrolyzed by absorbed water, so that P and
B atoms are segregated on the BPSG film surface. Also, P and
B atoms are more segregated in the reflow process when the
BPSG film, having absorbed moisture, s reflowed.
Therefore, by preventing the absorption of moisture onto the
BPSG film, that is, by making the BPSG film surface hydrophobic, the segregation of the impurities such as P and
B from the BPSG film can be restrained.
Here, as the organic compound gas containing hydrocarbon, there can be used alcohol of an aliphatic hydrocarbon system such as isopropyl alcohol, and isobutyl alcohol, especially alcohol of a normal chain system such as methyl alcohol, ethyl alcohol, propyl alcohol, ethylene glycol, phenol such as cresol and so on, ether such as ethyl ether, methyl ether, ethyl ether, propyl ether, aldehyde such as formaldehyde, acetaldehyde, propionaldehyde and so on, and hexaalkyl disiloxane such as hexamethyl disiloxane ([(CH3)3Si]20). However, the organic compound gas is not limited to these.
Next, as shown in Fig. 2B, by performing heat treatment in a nitrogen ambience at a temperature equal to or higher than 850 "C, e.g., at a temperature of about 900 "C for 5 to 30 minutes, the BPSG film 4 is reflowed and completely flattened.
according to the first embodiment of the present invention, the BPSG film surface which is made hydrophobic has the functions of the prevention of segregation of impurities such as P and B and the prevention of absorption of moisture. Because diffusion of the impurities from the
BPSG film surface is restrained, the present invention is superior in the flattening shape to the conventional case where the BPSG film surface is not made hydrophobic, when the
BPSG film is formed with the same concentrations of P and B.
Also, according to the first embodiment of the present invention, it is possible to increase the production yield of semiconductor device by about 20%ion orrlyn to the conventional manufacturing process. Further, there are the effects of reduction of the generation of a short-circuit fault between metal wirings because of remaining metal at a step portion of the interlayer insulating film as the result of improvement of surface flatness, and reduction of focus fault in the lithography process, in addition to reduction of the short-circuit fault by the segregation of the impurities from the BPSG film.
Next, the method of manufacturing a semiconductor device according to the second embodiment of the present invention will be described.
In the above first embodiment, the reflow process is performed using the heat treatment in the nitrogen ambience at the temperature of about 900 "C. However, in the second embodiment, a low temperature reflow process is performed at the temperature of about 800 to 850 C. In order to perform the low temperature reflow process and further to get a good flattened shape, the total concentration of phosphorus (P) and boron (B) is preferably equal to or higher than 25, and more preferably equal to or higher than 30 mol%. On the other hand, because the segregation limit total concentration of P and B from the BPSG film is about 18 mol%, it is difficult to prevent impurity segregation in a usual method of forming the BPSG film. Therefore, the BPSG film surface must be made more hydrophobic than in the first embodiment.
First, as in Fig. 2A, by the CVD method using TEOS Oj system gas, the BPSG film of a desired film thickness is grown to which phosphorus (P) atoms and boron (B) atoms are added with the concentration of 5 to 10 mol% and the concentration of 15 to 25 mol%, respectively.
Next, like the first embodiment, the BPSG film surface is made hydrophobic. For this purpose, a substrate temperature is first raised from thetepperaturintheranof400to 550 oCwwhich is generally used to form the BPSG film to the temperature equal to or higher than 650 "C at which -OH groups start elimination. Further, ethyl alcohol gas is supplied in 30 to 100 sccm (cm3/minute) and (02 + 03) gas is supplied in 5.0 to 10.0 SLM in the 03 concentration of 250 to 350 g/l. As a result, the -OH group on the BPSG film surface is substituted by -OC2Hs group. If the concentration of 03 gaS is about twice more than in the first embodiment while the substrate temperature is maintained at the temperature equal to or higher than 650 "C, the substitution efficiency increases. However, if a thermal history is taken into account, it is desirable that the substrate temperature is 650 to 700 "C. Thereafter, heat treatment is performed in nitrogen ambience at the temperature of 800 to 850 "C for 5 to 30 minutes such that the BPSG film is reflowed for the flattening.
In the second embodiment, the same flattening shape as in the first embodiment can te obtained by the effect of high total concentration of phosphorus and boron, even if the heat treatment is performed at the low temperature of 800 to 850 "C. Further, the method in the second embodiment can cope with the low temperature reflow process. The method is advantageous in the prevention of expansion of shallow diffusion layers which is required in the advanced semiconductor devices.
In the above first and second embodiments, the CvD method using TEOS - 03 system gas is used for the method of forming the BPSG film. This is because the process provides
the highest productivity.
In the present invention, the segregation of impurities from the BPSG film can be prevented. If the BPSG film surface can be made hydrophobic, the other processes and whatever equipment may be used.
Also, in the present invention, ethyl alcohol is selected as the gas used to make the film surface hydrophobic. This is because the material is comparatively cheap and there is not a problem in safety. However, in the present invention, like the CVD method, any material which become possible to make the film surface hydrophobic, i.e., organic material may be used.
As described above, in the present invention, a silicon oxide film with a low melting point which contains P and B atoms is formed as the interlayer insulating film. The hydrophobic processing of the BPSG film surface is performed using organic compound gas which contains hydrocarbon and 03 gas. Thereby, the moisture absorption and the diffusion of P and B atoms from the film surface can be prevented. In this manner, there is an effect that it is possible to achieve the semiconductor device and the method of manufacturing the same in which the interlayer insulating film is superior in the reflow shape while the segregation of the impurities is restrained.
Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other disclosed and/or illustrated features.
The text of the abstract filed herewith is repeated here as part of the specification.
In a method of manufacturing a semiconductor device, a BPSG film is formed as an interlayer insulating film. Hydrophobic processing is applied to the BPSG film for making a surface of the BPSG film hydrophobic after the BPSG film is formed.
Then, the BPSG film is reflowed such that the BPSG film surface is flattened, after
the hydrophobic processing.
Claims (23)
1. A method of manufacturing a semiconductor device, comprising the steps of:
forming a boron phosphorus silicate glass (BPSG) layer;
performing a hydrophobic processing to make a surface of said BPSG layer hydrophobic; and
subsequently heating said BPSG layer to flatten said surface of said BPSG layer.
2. A method according to Claim 1, wherein the concentrations of phosphorous and boron atoms in said BPSG layer are lower than a segregation limit concentration of P and B atoms respectively.
3. A method according to Claim 2, wherein said hydrophobic processing is performed at the same temperature as said step of forming said BPSG layer.
4. A method according to Claim 2 or 3, wherein said hydrophobic processing includes supplying an organic compound gas and a gas comprising O2 and 03 with an 03 concentration in the range from 90 to 120 gll to said BPSG layer.
5. A method according to Claim 2, 3 or 4, wherein said heating step comprises heating said BPSG layer at approximately 900"C.
6. A method according to Claim 1, wherein the concentrations of phosphorous and boron atoms in said BPSG film are equal to or higher than a segregation limit concentration of P and B atoms respectively.
7. A method according to Claim 6, wherein said hydrophobic processing is performed at a higher temperature than said step of forming a BPSG layer.
8. A method according to Claim 6 or 7, wherein said hydrophobic processing is performed at a temperature in the range from 650 to 700"C.
9. A method according to Claim 6, 7 or 8, wherein said hydrophobic processing includes supplying an organic compound gas and a gas comprising O2 and O3 with an 03 concentration in the range from 250 to 350 g/l to said BPSG layer.
10. A method according to any of Claims 6 to 9, wherein said heating comprises heating said BPSG layer at a temperature in the range from 800 to 850"C.
11. A method according to any preceding claim, wherein said hydrophobic processing comprises substituting an organic group containing hydrocarbon for a hydroxyl group on said BPSG layer surface using an organic compound gas.
12. A method according to Claim 11, wherein said organic compound gas is selected from the group consisting of alcohol, phenol, ether, aldehyde and hexaalkyl disiloxane.
13. A method according to Claim 12, wherein said alcohol is a normal chain hydrocarbon alcohol.
14. A method according to Claim 13, wherein said alcohol is methyl alcohol.
15. A method according to Claim 11, wherein said organic group includes hydrocarbon.
16. A method according to Claim 11, wherein said organic group is an ethoxyl group or other alkoxyl group.
17. A method according to any preceding claim wherein said BPSG layer is an interlayer.
18. A semiconductor device comprising:
a conductive circuit pattern formed on a semiconductor substrate; and
an insulating interlayer formed on said substrate including said circuit pattern, and having a hydrophobic layer on a surface thereof.
19. A semiconductor device according to Claim 18, wherein said hydrophobic layer includes organic groups each containing hydrocarbon.
20. A semiconductor device according to Claim 19, wherein said organic group is an alkoxyl group.
21. A semiconductor device according to Claim 20, wherein said alkoxyl group is an ethoxyl group.
22. A method of manufacturing a semiconductor device substantially as herein described with reference to Figures 2A, 2B, 3A and 3B of the accompanying drawings.
23. A semiconductor device substantially as herein described with reference to and as shown in Figure 2B of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9704056A GB2322734A (en) | 1997-02-27 | 1997-02-27 | Semiconductor device and a method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9704056A GB2322734A (en) | 1997-02-27 | 1997-02-27 | Semiconductor device and a method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9704056D0 GB9704056D0 (en) | 1997-04-16 |
| GB2322734A true GB2322734A (en) | 1998-09-02 |
Family
ID=10808390
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9704056A Withdrawn GB2322734A (en) | 1997-02-27 | 1997-02-27 | Semiconductor device and a method of manufacturing the same |
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| GB (1) | GB2322734A (en) |
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| GB893859A (en) * | 1958-07-21 | 1962-04-11 | Pacific Semiconductors Inc | Improved surface treatment of semiconductor bodies |
| GB2235444A (en) * | 1989-05-31 | 1991-03-06 | Mitel Corp | A method of producing insulating layers |
| EP0421203A1 (en) * | 1989-09-28 | 1991-04-10 | Applied Materials, Inc. | An integrated circuit structure with a boron phosphorus silicate glass composite layer on semiconductor wafer and improved method for forming same |
| WO1991019317A1 (en) * | 1990-05-29 | 1991-12-12 | Mitel Corporation | Sog with moisture resistant protective capping layer |
| EP0497541A1 (en) * | 1991-01-28 | 1992-08-05 | Kawasaki Steel Corporation | Semiconductor device with a borophosphosilicate glass and method of manufacturing the same |
| EP0519393A2 (en) * | 1991-06-20 | 1992-12-23 | Semiconductor Process Laboratory Co., Ltd. | Method for planarizing a semiconductor substrate surface |
| EP0540321A1 (en) * | 1991-10-30 | 1993-05-05 | Samsung Electronics Co. Ltd. | A method for fabricating an interlayer-dielectric film of semiconductor device |
| GB2294651A (en) * | 1994-11-02 | 1996-05-08 | Hyundai Electronics Ind | Minimising moisture absorption |
| GB2301224A (en) * | 1995-05-22 | 1996-11-27 | Hyundai Electronics Ind | Method of forming a SOG film in a semiconductor device |
| GB2308735A (en) * | 1995-12-23 | 1997-07-02 | Hyundai Electronics Ind | A method of manufacturing a semiconductor device |
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1997
- 1997-02-27 GB GB9704056A patent/GB2322734A/en not_active Withdrawn
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB893859A (en) * | 1958-07-21 | 1962-04-11 | Pacific Semiconductors Inc | Improved surface treatment of semiconductor bodies |
| GB2235444A (en) * | 1989-05-31 | 1991-03-06 | Mitel Corp | A method of producing insulating layers |
| EP0421203A1 (en) * | 1989-09-28 | 1991-04-10 | Applied Materials, Inc. | An integrated circuit structure with a boron phosphorus silicate glass composite layer on semiconductor wafer and improved method for forming same |
| WO1991019317A1 (en) * | 1990-05-29 | 1991-12-12 | Mitel Corporation | Sog with moisture resistant protective capping layer |
| EP0497541A1 (en) * | 1991-01-28 | 1992-08-05 | Kawasaki Steel Corporation | Semiconductor device with a borophosphosilicate glass and method of manufacturing the same |
| EP0519393A2 (en) * | 1991-06-20 | 1992-12-23 | Semiconductor Process Laboratory Co., Ltd. | Method for planarizing a semiconductor substrate surface |
| EP0540321A1 (en) * | 1991-10-30 | 1993-05-05 | Samsung Electronics Co. Ltd. | A method for fabricating an interlayer-dielectric film of semiconductor device |
| GB2294651A (en) * | 1994-11-02 | 1996-05-08 | Hyundai Electronics Ind | Minimising moisture absorption |
| GB2301224A (en) * | 1995-05-22 | 1996-11-27 | Hyundai Electronics Ind | Method of forming a SOG film in a semiconductor device |
| GB2308735A (en) * | 1995-12-23 | 1997-07-02 | Hyundai Electronics Ind | A method of manufacturing a semiconductor device |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9704056D0 (en) | 1997-04-16 |
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