Patent CH354704A successfully refreshed from Google Patents.
US4636280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the pretreatment of a substrate for ion implantation
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1984-08-21
•
Granted: 1987-01-13
•
Expires: 2004-08-21
Abstract
Abstract An IC wafer with a uniform distribution of impurities is obtained by a pretreatment comprising annealing a semiconductor substrate at a high temperature for a long period of time and then cooling rapidly before IC processing.
Inventors
- 👤 Ryusuke Nakai
- 👤 Toshihiko Takebe
- 👤 Hajime Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:39
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/206; H10P30/21; H10P30/28; H10P36/00; H10P36/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A method for the pretreatment of a semiconductor substrate, which comprises annealing a substrate consisting of a material selected from the Group III-V compounds containing impurities therein at a high temperature for a long period of time sufficient to uniformly distribute the impurities throughout the substrate and then quenching the substrate to freeze the impurities in a uniform state throughout the substrate before IC processing.
Claim 2
Independent Claim
65 words
A method for the pretreatment of a semiconductor substrate, which comprises annealing a substrate consisting of a material selected from the Group III-V compounds containing impurities therein at a high temperature for a long period of time sufficient to uniformly distribute the impurities throughout the substrate and then quenching the substrate to freeze the impurities in a uniform state throughout the substrate before IC processing.
Claim 3
Dependent Claim
25 words
The method of claim 1, wherein the annealing is carried out at a temperature of 800° to 1100° C. for 10 minutes to 500 hours.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the annealing is carried out under As pressure.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein the quenching is carried out at a cooling rate of 5° C./min to 500° C./min.
Claim 6
Dependent Claim
18 words
The method of claim 1, wherein the quenching is followed by IC processing including an activating annealing treatment.
Claim 7
Dependent Claim
26 words
The method of claim 6, wherein the activation annealing is carried out at a lower temperature for a shorter period of time than in the pretreatment.
Claim 8
Dependent Claim
41 words
The method of claim 1 wherein the annealing is carried out at a temperature of 800° to 1100° C. for 10 minutes to 500 hours and the quenching is carried out at a cooling rate of 5° C./min to 500° C./min.
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) | 1990-01-12 | 1990-07-14 | 1991-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-12 | 1994-07-14 | 1995-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-12 | 1998-07-14 | 1999-01-13 | $7700.00 | Window Closed / Lapsed |