Patent US4575920A successfully refreshed from Google Patents.
US4575920A
Expired / Lapsed
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Method of manufacturing an insulated-gate field-effect transistor
Assignee: Toshiba Corp
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Filing: 1984-05-02
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Granted: 1986-03-18
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Expires: 2004-05-02
Abstract
Abstract A method of manufacturing an insulated-gate field-effect transistor on a silicon substrate at high density for large scale integration is disclosed. The source and drain regions of the transistor are formed by implanting low density impurity ions into the silicon substrate and then heating the substrate at a temperature in the range of 900° to 1300° C. Thereafter, additional ions are implanted into the source and drain regions, and the substrate is heated at a second temperature of 700° C., or lower, to provide good ohmic contact between metal electrodes and the source and drain regions. In addition, the sheet resistivity of the source and drain regions is small so that high speed operation of the transistor is achieved.
Inventors
- 👤 Yoshitaka Tsunashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:28
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/60; H10D30/601; H10D30/605; H10D62/00; H10D62/80; H10D62/83; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/20; H10D64/23; H10D64/251; H10D64/258; H10D64/259; H10D64/60; H10D64/62; H10D64/66; H10D64/661; H10D64/662
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
161 words
A method of manufacturing an insulated-gate field-effect transistor on a silicon substrate of a first conductivity type comprising the steps of: (a) forming an insulating layer around a predetermined surface portion of said substrate; (b) forming a gate insulating film and a gate electrode on a portion of said predetermined surface portion, said gate electrode being formed on said gate insulating film; (c) implanting impurity ions into said predetermined surface portion between said insulating layer and said gate elecctrode to form source and drain regions of a second conductivity type having a low impurity concentration, said source and drain regions being spaced apart; (d) heating said substrate at a first temperature in the range of 900° to 1300° C.; (e) implanting ions of said second conductivity type into said source and drain regions; (f) heating said substrate at a second temperature at or below 700° C.; and (g) forming metal electrodes in ohmic contact with said source and drain regions, respectively.
Claim 2
Independent Claim
161 words
A method of manufacturing an insulated-gate field-effect transistor on a silicon substrate of a first conductivity type comprising the steps of: (a) forming an insulating layer around a predetermined surface portion of said substrate; (b) forming a gate insulating film and a gate electrode on a portion of said predetermined surface portion, said gate electrode being formed on said gate insulating film; (c) implanting impurity ions into said predetermined surface portion between said insulating layer and said gate elecctrode to form source and drain regions of a second conductivity type having a low impurity concentration, said source and drain regions being spaced apart; (d) heating said substrate at a first temperature in the range of 900° to 1300° C.; (e) implanting ions of said second conductivity type into said source and drain regions; (f) heating said substrate at a second temperature at or below 700° C.; and (g) forming metal electrodes in ohmic contact with said source and drain regions, respectively.
Claim 3
Dependent Claim
23 words
A method according to claim 1 wherein the ions implanted by step (e) increase the impurity concentration of said source and drain regions.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein the ions implanted by step (e) are silicon ions.
Claim 5
Dependent Claim
24 words
A method according to claim 1 wherein the ions implanted by step (c) are selected from the group consisting of As, P and B.
Claim 6
Dependent Claim
24 words
A method according to claim 1 wherein the ions implanted by step (e) are selected from the group consisting of As, P and B.
Claim 7
Dependent Claim
26 words
A method according to claim 1 wherein said ions are implanted into said substrate in steps (c) and (e) using said gate electrode as a mask.
Claim 8
Dependent Claim
19 words
A method according to claim 1 wherein said second temperature is in the range of 500° to 700° C.
Claim 9
Dependent Claim
21 words
A method according to claim 1 wherein all steps subsequent to heating step (f) are performed at or below 700° C.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein said metal electrodes are made of aluminum or tungsten.
Claim 11
Dependent Claim
46 words
A method according to claim 1 wherein each of said metal electrodes comprises a refractory metal film in contact with said source and drain regions and an aluminum film formed on said refractory metal film, said refractory metal film being formed by selective chemical vapor deposition.
Claim 12
Dependent Claim
37 words
A method according to claim 10 further comprising the step of forming an insulating film on the sidewalls of said gate electrode before formation of said metal electrodes and after heating said substrate at said second temperature.
Claim 13
Dependent Claim
20 words
A method according to claim 11 wherein said metal electrodes substantially cover the surface of said source and drain regions.
Claim 14
Dependent Claim
26 words
A method according to claim 1 wherein the dose of said impurity ions is on the order of 10 13 to 10 15 cm -2 .
Claim 15
Dependent Claim
29 words
A method according to claim 1 wherein the dose of said ions implanted in step (e) is on the order of 10 14 to 10 16 cm -2 .
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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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |