US4016006A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of heat treatment of wafers
Assignee: Hitachi Ltd
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Filing: 1976-03-16
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Granted: 1977-04-05
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Expires: 1996-03-16
Abstract
Abstract In a method of heat-treating a number of wafers each of which consists of a substance of poor heat conduction and a semiconductor layer formed on one surface of the substance, a method of heat treatment of wafers characterized in that the heat treatment is carried out under the state under which an auxiliary wafer made of a substance of good heat conduction is held in proximity to the other surface of the substance of poor heat conduction, whereby the wafers for the heat treatment are prevented from being cracked and have the characteristics made uniform.
Inventors
- 👤 Akira Yoshinaka
- 👤 Takaaki Aoshima
- 👤 Yoshimitsu Sugita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:04
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; C; C30; C30B; C30B31/00; C30B31/06; C30B31/12; C30B33/00; C30B33/005; Y; Y10; Y10S; Y10S148/00; Y10S148/118; Y10S148/15
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
In a method of heat-treating a number of wafers each of which consists of a substance of poor heat conduction and a semiconductor layer formed on one surface thereof, said method of heat treatment of wafers comprising the fact that the treatment is performed under the state under which an auxiliary wafer made of a substance of good heat conduction is held in proximity to that surface of said substance of poor heat conduction which is opposite to said one surface.
Claim 2
Dependent Claim
81 words
In a method of heat-treating a number of wafers each of which consists of a substance of poor heat conduction and a semiconductor layer formed on one surface thereof, said method of heat treatment of wafers comprising the fact that the treatment is performed under the state under which an auxiliary wafer made of a substance of good heat conduction is held in proximity to that surface of said substance of poor heat conduction which is opposite to said one surface.
Claim 3
Dependent Claim
35 words
The method of heat treatment of wafers according to claim 1, wherein said substance of poor heat conduction is sapphire, while said semiconductor layer formed on one surface thereof is made of silicon single crystal.
Claim 4
Dependent Claim
19 words
The method of heat treatment of wafers according to claim 2, wherein said auxiliary wafer is made of silicon.
Claim 5
Dependent Claim
33 words
The method of heat treatment of wafers according to claim 3, wherein a spacing between said wafer of poor heat conduction and said auxiliary wafer of good heat conduction is about 5 mm.
Claim 6
Dependent Claim
73 words
In a method of heat-treating a number of wafers each of which consists of a substance of poor heat conduction and a semiconductor layer formed on one surface thereof, said method of heat treatment of wafers comprising the fact that the heat treatment is performed under the state under which the wafers of poor heat conduction and auxiliary wafers of good heat conduction are erected on a wafer jig alternately and in proximity.
Claim 7
Dependent Claim
73 words
In a method of heat-treating a number of wafers each of which consists of a substance of poor heat conduction and a semiconductor layer formed on one surface thereof, said method of heat treatment of wafers comprising the fact that the heat treatment is performed under the state under which the wafers of poor heat conduction and auxiliary wafers of good heat conduction are erected on a wafer jig alternately and in proximity.
Claim 8
Dependent Claim
37 words
The method of heat treatment of wafers according to claim 5, wherein said wafers of poor heat conduction and said wafers of good heat conduction are erected at respectively equal intervals and orthogonally to said wafer jig.
Claim 9
Dependent Claim
37 words
The method of heat treatment of wafers according to claim 5, wherein said wafers of poor heat conduction and said wafers of good heat conduction are erected at respectively equal intervals and aslant against said wafer jig.
Claim 10
Dependent Claim
34 words
The method of heat treatment of wafers according to claim 1, wherein the space between said wafer of poor heat conduction and said auxiliary wafer of good heat conduction is 2 to 30 millimeters.
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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |