US4920920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for producing semiconductor devices
Assignee: Mitsubishi Electric Corp
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Filing: 1988-08-23
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Granted: 1990-05-01
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Expires: 2008-08-23
Abstract
Abstract An apparatus for producing semiconductor devices has a hollow reaction tube which receives a boat carrying a row of a multiplicity of semiconductor wafers held in vertical posture. A flow stabilizing member is disposed in the vicinity of the wafer which is on the downstream end of the wafer row as viewed in the direction of flow of a treating gas introduced into the reaction tube. The flow stabilizing member has such configuration as to progressively converge towards the downstream end of the reaction tube and the maximum-diameter of the flow stabilizing member is substantially the same as that of the wafer. The flow stabilizing member effectively prevents generation of any turbulency of the reaction gas in the region near the downstream end of the reaction tube so that induction of air into the reaction tube which may otherwise be caused by the turbulency is avoided. In consequence, degradation of the quality of product semiconductor devices is avoided and yield is improved.
Inventors
- 👤 Susumu Shigeki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:21
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/455; C23C16/45587; C23C16/45591; Y; Y10; Y10S; Y10S156/00; Y10S156/913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
149 words
An apparatus for producing semiconductor devices comprising: a hollow reaction tube having opposed first and second ends; reaction gas supplying means provided on said first end of said reaction tube for introducing a reaction gas into said reaction tube to flow toward said second end; a boat received in said reaction tube for carrying a multiplicity of semiconductor wafers having a diameter, arranged in a row, and held transverse to said gas flow; a flow stabilizing member disposed in said reaction tube near the second end of said reaction tube, said flow stabilizing member having a maximum diameter substantially the same as that of wafers held in said boat, the cross-sectional area of said flow stabilizing member progressively decreasing toward said second end of said reaction tube; and a duct provided on said second end of said reaction tube for discharging reaction gas to the exterior of said apparatus.
Claim 2
Independent Claim
149 words
An apparatus for producing semiconductor devices comprising: a hollow reaction tube having opposed first and second ends; reaction gas supplying means provided on said first end of said reaction tube for introducing a reaction gas into said reaction tube to flow toward said second end; a boat received in said reaction tube for carrying a multiplicity of semiconductor wafers having a diameter, arranged in a row, and held transverse to said gas flow; a flow stabilizing member disposed in said reaction tube near the second end of said reaction tube, said flow stabilizing member having a maximum diameter substantially the same as that of wafers held in said boat, the cross-sectional area of said flow stabilizing member progressively decreasing toward said second end of said reaction tube; and a duct provided on said second end of said reaction tube for discharging reaction gas to the exterior of said apparatus.
Claim 3
Dependent Claim
17 words
An apparatus according to claim 1 wherein said flow stabilizing member is detachably fixed to said boat.
Claim 4
Dependent Claim
17 words
An apparatus according to claim 1 wherein said flow stabilizing member is formed integrally with said boat.
Claim 5
Dependent Claim
15 words
An apparatus according to claim 1 wherein said flow stabilizing member has a conical form.
Claim 6
Dependent Claim
19 words
An apparatus according to claim 1 wherein said flow stabilizing member has a stream-lined configuration with a rounded end.
Claim 7
Dependent Claim
62 words
An apparatus according to claim 1 further comprising an additional flow stabilizing member disposed in said reaction tube near said first end, said additional flow stabilizing member having a maximum diameter substantially the same as the diameter of wafers held in said boat, the cross-sectional area of said additional flow stabilizing member progressively decreasing toward said first end of said reaction tube.
Claim 8
Dependent Claim
17 words
An apparatus according to claim 6 wherein said flow stabilizing member is detachably fixed to said boat.
Claim 9
Dependent Claim
17 words
An apparatus according to claim 6 wherein said flow stabilizing member is formed integrally with said boat.
Claim 10
Dependent Claim
15 words
An apparatus according to claim 6 wherein said flow stabilizing member has a conical form.
Claim 11
Dependent Claim
19 words
An apparatus according to claim 6 wherein said flow stabilizing member has a stream-lined configuration with a rounded end.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |