US4515755A
Expired / Lapsed
US
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Apparatus for producing a silicon single crystal from a silicon melt
Assignee: Coorstek KK
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Filing: 1982-04-14
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Granted: 1985-05-07
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Expires: 2002-04-14
Abstract
Abstract An apparatus for producing silicon single crystal from melted silicon by the pull-up process using a seed crystal, wherein at least a portion of a device in contact with the melted silicon includes a layer of silicon nitride precipitated from gaseous phase and comprising 20% or above of β phase, or comprising 80% or above of α phase whose crystal grains have grain diameters of 5 μm or above at a ratio of 10% or more.
Inventors
- 👤 Shuitsu Matsuo
- 👤 Yasuhiro Imanishi
- 👤 Hideo Nagashima
- 👤 Masaharu Watanabe
- 👤 Toshiro Usami
- 👤 Hisashi Muraoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:58
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C30; C30B; C30B15/00; C30B15/10; C30B15/20; C30B15/22; C30B15/24; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1032
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
64 words
In an apparatus for production silicon single crystal by seed pulling from a melt contained in a crucible for molten silicon, the improvement which comprises on at least a portion of the surfaces of said crucible which comes in contact with said silicon melt include a layer comprised of silicon nitride precipitated from a gaseous phase and containing at least 20% of β phase.
Claim 2
Dependent Claim
64 words
In an apparatus for production silicon single crystal by seed pulling from a melt contained in a crucible for molten silicon, the improvement which comprises on at least a portion of the surfaces of said crucible which comes in contact with said silicon melt include a layer comprised of silicon nitride precipitated from a gaseous phase and containing at least 20% of β phase.
Claim 3
Dependent Claim
55 words
The apparatus of claim 1, which further comprises a die which extends into contact with the melt and is provided on at least a portion of the surfaces which come in contact with said melt with a layer comprised of silicon nitride percipated from a gaseous phase and containing at least 20% of β phase.
Claim 4
Dependent Claim
81 words
In an apparatus for growing silicon single crystal by seed pulling from a silicon melt contained in a crucible for molten silicon, the improvement which comprises on at least a portion of the surfaces of said crucible which comes in contact with said silicon melt include a layer comprising silicon nitride precipitated from gaseous phase and comprising at least 80% of α phase, at least 10% of the crystal grains of said phase having a length of at least 5 microns.
Claim 5
Dependent Claim
81 words
In an apparatus for growing silicon single crystal by seed pulling from a silicon melt contained in a crucible for molten silicon, the improvement which comprises on at least a portion of the surfaces of said crucible which comes in contact with said silicon melt include a layer comprising silicon nitride precipitated from gaseous phase and comprising at least 80% of α phase, at least 10% of the crystal grains of said phase having a length of at least 5 microns.
Claim 6
Dependent Claim
34 words
The apparatus according to claim 1 or 3, wherein the silicon nitride layer contains as impurities less than 3 ppm of boron, less than 5 ppm of aluminum, less than 10 ppm of iron.
Claim 7
Dependent Claim
28 words
The apparatus according to claim 1 or 3, wherein said silicon nitride layer has a smooth surface with the surface roughness being no more than 400μπ in Hmax.
Claim 8
Dependent Claim
18 words
The apparatus according to claim 5, wherein the surface roughness is no more than 25 μm in Hmax.
Claim 9
Dependent Claim
24 words
The apparatus according to claim 1 or 3 wherein said apparatus further includes a heat-resistive base member having the silicon nitride layer deposited thereon.
Claim 10
Dependent Claim
26 words
The apparatus according to claim 7, wherein the base member is made of a material selected from the group consisting of carbon, silicon and silicon carbide.
Claim 11
Dependent Claim
15 words
The apparatus according to claim 7, wherein the base member is made of silicon nitride.
Claim 12
Dependent Claim
36 words
The apparatus according to claim 7, wherein the base member includes as impurities less than 250 ppm of iron, less than 50 ppm of copper, and has a porosity in the range of 10 to 40%.
Claim 13
Dependent Claim
69 words
The apparatus of claim 3, which further comprises a die extending into contact with the melt and which is provided with, on at least a portion of the surfaces in contact with said melt, a layer comprising silicon nitride precipated from gaseous phase and comprising at least 80% of α phase, at least 10% of the crystal grains of said phase having a length of at least 5 microns.
References Cited (Backward Citations)
US4312923A
Cited
US4213940A
Cited
US4090851A
Cited
JPS54107833A
Cited
JPS54157779A
Cited
JPS5567514A
Cited
US4264565A
Cited
US4368180A
Cited
US4298629A
Cited
US4346068A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |