US5037503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for growing silicon single crystal
Assignee: Nippon Steel Corp
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Filing: 1989-05-26
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Granted: 1991-08-06
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Expires: 2009-05-26
Abstract
Abstract A method for growing silicon single crystal uses as materials, silicon granules prepared by the silane process and having a residual hydrogen concentration of 7.5 wtppm or less, silicon granules prepared by the trichlorosilane process and having a residual chlorine concentration of 15 wtppm or less. In the case where such silicon granules are used, a bursting phenomenon does not occur when the silicon granules are melted. As a result, there is no scattered matter due to the bursting phenomenon, whereby the growth condition of the single crystal is not disturbed.
Inventors
- 👤 Tsutomu Kajimoto
- 👤 Daizou Horie
- 👤 Shin-ichi Sakurada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:39
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C30B15/00; C30B15/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
75 words
A method for producing silicon single crystal using silicon granules, comprising: preparing powdered silicon; growing silicon granules by decomposing silane gas on the surface of said powdered silicon; heating said silicon granules in an atmosphere of an inert gas so as to have a residual hydrogen concentration of 7.5 wtppm or less; and growing silicon single crystal by pulling a silicon seed crystal from a melt of liquid silicon prepared by melting said silicon granules.
Claim 2
Independent Claim
75 words
A method for producing silicon single crystal using silicon granules, comprising: preparing powdered silicon; growing silicon granules by decomposing silane gas on the surface of said powdered silicon; heating said silicon granules in an atmosphere of an inert gas so as to have a residual hydrogen concentration of 7.5 wtppm or less; and growing silicon single crystal by pulling a silicon seed crystal from a melt of liquid silicon prepared by melting said silicon granules.
Claim 3
Dependent Claim
71 words
A method for producing silicon single crystal as set forth in claim 1, wherein in the step of growing silicon single crystal, said silicon granules are put in a crucible and melted, said silicon seed crystal is brought into contact with said melt of liquid silicon in said crucible, and said silicon single crystal growing at an end of with said seed crystal is pulled up together with said seed crystal.
Claim 4
Dependent Claim
35 words
A method for producing silicon single crystal as set forth in claim 1, wherein in the step of growing silicon single crystal, said silicon granules are supplied in a crucible as additional charge silicon materials.
Claim 5
Dependent Claim
27 words
A method for producing silicon single crystal as set forth in claim 3, wherein said silicon granules are supplied in said crucible as initial charge silicon materials.
Claim 6
Dependent Claim
109 words
A method for producing silicon single crystal as set forth in claim 1, wherein in the step of growing silicon single crystal, a bulkhead for dividing a crucible into an inner region and an outer region is provided in said crucible in the state that both regions communicate with each other under a surface of said liquid silicon, said silicon seed crystal is brought into contact with said liquid silicon in said inner region, said silicon granules are supplied into said outer region as additional charge silicon materials, and said silicon single crystal growing at an end of said seed crystal is pulled up together with said seed crystal.
Claim 7
Dependent Claim
31 words
A method for producing silicon single crystal as set forth in claim 5, wherein said silicon granules are supplied into said inner region of said crucible as initial charge silicon materials.
Claim 8
Dependent Claim
33 words
A method for producing silicon single crystal as set forth in claim 5, wherein said silicon granules are supplied into said outer region from plural positions in a circumferential direction of said crucible.
Claim 9
Independent Claim
77 words
A method for producing silicon single crystal using silicon granules, comprising: preparing powdered silicon; growing silicon granules by reducing trichlorosilane gas on the surface of said powdered silicon, wherein the growth rate of silicon is set to more than 0.4 μm/min so as to have a residual chlorine concentration of 15 wtppm or less; and growing silicon single crystal by pulling a silicon seed crystal from a melt of liquid silicon prepared by melting said silicon granules.
Claim 10
Independent Claim
77 words
A method for producing silicon single crystal using silicon granules, comprising: preparing powdered silicon; growing silicon granules by reducing trichlorosilane gas on the surface of said powdered silicon, wherein the growth rate of silicon is set to more than 0.4 μm/min so as to have a residual chlorine concentration of 15 wtppm or less; and growing silicon single crystal by pulling a silicon seed crystal from a melt of liquid silicon prepared by melting said silicon granules.
Claim 11
Dependent Claim
70 words
A method for producing silicon single crystal as set forth in claim 8, wherein in the step of growing silicon single crystal, said silicon granules are put in a crucible and melted, said silicon seed crystal is brought into contact with said melt of liquid silicon in said crucible, and said silicon single crystal growing at an end of said seed crystal is pulled up together with said seed crystal
Claim 12
Dependent Claim
35 words
A method for producing silicon single crystal as set forth in claim 8, wherein in the step of growing silicon single crystal, said silicon granules are supplied in said crucible as additional charge silicon materials.
Claim 13
Dependent Claim
27 words
A method for producing silicon single crystal as set forth in claim 10, wherein said silicon granules are supplied in said crucible as initial charge silicon materials.
Claim 14
Dependent Claim
109 words
A method for producing silicon single crystal as set forth in claim 8, wherein in the step of growing silicon single crystal, a bulkhead for dividing a crucible into an inner region and an outer region is provided in said crucible in the state that both regions communicate with each other under a surface of said liquid silicon, said silicon seed crystal is brought into contact with said liquid silicon in said inner region, said silicon granules are supplied into said outer region as additional charge silicon materials, and said silicon single crystal growing at an end of said seed crystal is pulled up together with said seed crystal.
Claim 15
Dependent Claim
31 words
A method for producing silicon single crystal as set forth in claim 12, wherein said silicon granules are supplied into said inner region of said crucible as initial charge silicon materials.
Claim 16
Dependent Claim
33 words
A method for producing silicon single crystal as set forth in claim 12, wherein said silicon granules are supplied into said outer region from plural positions in a circumferential direction of said crucible.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |