US4108686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an insulated gate field effect transistor by implanted double counterdoping
Assignee: RCA Corp
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Filing: 1977-07-22
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Granted: 1978-08-22
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Expires: 1997-07-22
Abstract
Abstract An insulated gate field effect transistor having spaced highly doped source and drain regions with less highly doped source and drain extensions, which define the ends of the channel of the transistor, has both the source and drain extensions and the channel of the transistor defined in a controllable manner by the steps of forming a continuous zone of the same conductivity type as the source and drain regions in the space between these two regions and then counterdoping a portion of this layer.
Inventors
- 👤 Lewis Alfred Jacobus, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:55
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/027; H10D30/0223; H10D30/0225; H10D30/60; H10D30/637; H10D62/00; H10D62/10; H10D62/17; H10D62/213; H10D62/221; H10D62/235; H10D62/299; H10D62/307; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/919
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
A method of making an insulated gate field effect transistor in a body of semiconductor material of one type conductivity and having a surface, said transistor having a channel region of predetermined length adjacent to said surface comprising the steps of forming a source region and a drain region each having a conductivity type opposite that of said body in said body adjacent to said surface, said regions having a predetermined distance therebetween greater than said predetermined length forming a zone having a conductivity type opposite to that of said body in said body adjacent to said surface, said zone extending between and being less conductive than said regions, forming said channel region by introducing conductivity modifiers of said one type into said zone over said predetermined length to convert that portion of said zone toward said one type conductivity, forming a gate insulator on said channel region, and forming a conductive gate on said gate insulator.
Claim 2
Independent Claim
157 words
A method of making an insulated gate field effect transistor in a body of semiconductor material of one type conductivity and having a surface, said transistor having a channel region of predetermined length adjacent to said surface comprising the steps of forming a source region and a drain region each having a conductivity type opposite that of said body in said body adjacent to said surface, said regions having a predetermined distance therebetween greater than said predetermined length forming a zone having a conductivity type opposite to that of said body in said body adjacent to said surface, said zone extending between and being less conductive than said regions, forming said channel region by introducing conductivity modifiers of said one type into said zone over said predetermined length to convert that portion of said zone toward said one type conductivity, forming a gate insulator on said channel region, and forming a conductive gate on said gate insulator.
Claim 3
Dependent Claim
74 words
The method of claim 1 wherein said step of forming said channel region is carried out by forming a masking layer on said surface, removing a portion of said masking layer located between said regions, the dimension of said portion of said surface in the direction between said regions being of said predetermined length to expose said surface, and introducing said conductivity modifiers of said one type into said body through said exposed surface.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein said step of forming said zone is accomplished by ion implanting conductivity modifiers into said body across all the surface thereof.
Claim 5
Dependent Claim
21 words
The method of claim 2 wherein the center of said predetermined length is coincident with the center of said predetermined distance.
Claim 6
Dependent Claim
18 words
The method of claim 2 wherein said step of forming said channel region is accomplished by ion implantation.
Claim 7
Dependent Claim
32 words
The method of claim 5 wherein said conductivity modifiers of said one type are introduced in an amount insufficient to convert said predetermined length of said zone to said one type conductivity.
Claim 8
Dependent Claim
32 words
The method of claim 5 wherein said conductivity modifiers of said one type are introduced in an amount adequate to convert said predetermined length of said zone to said one type conductivity.
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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) | 1981-08-21 | 1982-02-20 | 1982-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-21 | 1986-02-20 | 1986-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-21 | 1990-02-20 | 1990-08-22 | $7700.00 | Window Closed / Lapsed |