Patent US4259779A successfully refreshed from Google Patents.
US4259779A
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US
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Method of making radiation resistant MOS transistor
Assignee: RCA Corp
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Filing: 1977-08-24
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Granted: 1981-04-07
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Expires: 1997-08-24
Abstract
Abstract The radiation resistance of an MOS transistor is improved by making the transistor in a manner such that, after the gate insulation layer is formed, all further steps are carried out at a relatively low temperature, i.e., less than about 900° C. The source and drain regions are preferably formed by ion implantation with very little or no post implant thermal activation, and the metallization is applied by low temperature techniques.
Inventors
- 👤 Alfred C. Ipri
- 👤 Doris W. Flatley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:38
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; Y; Y10; Y10S; Y10S257/00; Y10S257/906; Y10S438/00; Y10S438/953
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
In a method of making an improved radiation tolerant MOS transistor which includes the steps of: (a) providing a channel oxide layer on a body of semiconductor material, (b) providing a gate on the channel oxide, (c) embedding a dopant in the semiconductor body on each side of the gate to form the source and drain regions, and (d) providing electrodes on the source and drain regions, the improvement comprising carrying out step (a) at a temperature no greater than 1000° C. and steps (b), (c), and (d) at a temperature no greater than 900° C.
Claim 2
Dependent Claim
96 words
In a method of making an improved radiation tolerant MOS transistor which includes the steps of: (a) providing a channel oxide layer on a body of semiconductor material, (b) providing a gate on the channel oxide, (c) embedding a dopant in the semiconductor body on each side of the gate to form the source and drain regions, and (d) providing electrodes on the source and drain regions, the improvement comprising carrying out step (a) at a temperature no greater than 1000° C. and steps (b), (c), and (d) at a temperature no greater than 900° C.
Claim 3
Dependent Claim
19 words
The method in accordance with claim 1 wherein the dopant is embedded in the semiconductor body by ion implantation.
Claim 4
Dependent Claim
35 words
The method in accordance with claim 2 wherein after the dopant is embedded in the semiconductor body, the body is heated at a temperature of no greater than 900° C. to activate the embedded ions.
Claim 5
Dependent Claim
29 words
The method in accordance with claim 3 wherein the ion implanted semiconductor body is heated to a temperature of no greater than 800° C. to activate the embedded ions.
Claim 6
Dependent Claim
40 words
The method in accordance with claim 1 wherein the gate is formed on the channel oxide by depositing a layer of polycrystalline silicon on the channel oxide and removing portions of the polycrystalline silicon layer to leave the gate portion.
Claim 7
Dependent Claim
28 words
The method in accordance with claim 5 in which the polycrystalline silicon layer is deposited by thermally decomposing silane at a temperature of no greater than 900° C.
Claim 8
Dependent Claim
50 words
The method in accordance with claim 6 wherein the portion of the polycrystalline silicon layer which is to form the gate is embedded with a dopant at a temperature no greater than 900° C. and the portion of the polycrystalline silicon layer which is not so embedded is then removed.
Claim 9
Dependent Claim
20 words
The method in accordance with claim 7 wherein the dopant is embedded in the polycrystalline silicon layer by ion implantation.
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) | 1984-04-06 | 1984-10-06 | 1985-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-06 | 1988-10-06 | 1989-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-06 | 1992-10-06 | 1993-04-07 | $7700.00 | Window Closed / Lapsed |