US3604107A
Expired / Lapsed
US
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Doped oxide field effect transistors
Assignee: Collins Radio Co
•
Filing: 1969-04-17
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Granted: 1971-09-14
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Expires: 1989-04-17
Abstract
Abstract Disclosed is a method of making a field effect transistor with an accurately aligned gate by forming the source and drain regions from a doped layer on the substrate surface. The resulting transistor has reduced internal capacitance and improved speed characteristics.
Inventors
- 👤 John R Fassett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:43
CPC Classifications
H; H10; H10D; H10D99/00; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10P; H10P32/00; H10P32/10; H10P32/14; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/043; Y10S148/049; Y10S148/053; Y10S148/106; Y10S148/141; Y10S148/151
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
171 words
The method of making a field effect transistor in a doped semiconductor substrate of a first conductivity type comprising the steps of 1. forming an undoped oxide layer on a surface of said substrate, 2. removing said undoped oxide layer from a first selected portion of said surface, 3. forming a doped oxide layer of a second conductivity type on said undoped oxide layer and on said first selected portion of said surface, 4. removing said doped oxide layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion, 5. forming an undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said doped oxide layer into said substrate thereby converting regions in said substrate directly beneath said doped oxide layer to the second conductivity type and 6. forming source and drain electrical contacts to said regions and a gate electrical contact on said undoped oxide layer on the surface of said second selected portion.
Claim 2
Independent Claim
171 words
The method of making a field effect transistor in a doped semiconductor substrate of a first conductivity type comprising the steps of 1. forming an undoped oxide layer on a surface of said substrate, 2. removing said undoped oxide layer from a first selected portion of said surface, 3. forming a doped oxide layer of a second conductivity type on said undoped oxide layer and on said first selected portion of said surface, 4. removing said doped oxide layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion, 5. forming an undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said doped oxide layer into said substrate thereby converting regions in said substrate directly beneath said doped oxide layer to the second conductivity type and 6. forming source and drain electrical contacts to said regions and a gate electrical contact on said undoped oxide layer on the surface of said second selected portion.
Claim 3
Dependent Claim
13 words
removing said undoped oxide layer from a first selected portion of said surface,
Claim 4
Dependent Claim
13 words
removing said undoped oxide layer from a first selected portion of said surface,
Claim 5
Dependent Claim
25 words
The method of making a field effect transistor as defined by claim 1 wherein said semiconductor material is silicon and said oxide is silicon oxide.
Claim 6
Dependent Claim
13 words
removing said undoped oxide layer from a first selected portion of said surface,
Claim 7
Dependent Claim
13 words
removing said undoped oxide layer from a first selected portion of said surface,
Claim 8
Dependent Claim
19 words
forming a thin highly doped layer of a second conductivity type on said first selected portion of said surface,
Claim 9
Dependent Claim
19 words
forming a thin highly doped layer of a second conductivity type on said first selected portion of said surface,
Claim 10
Dependent Claim
27 words
The method of making a field effect transistor as defined by claim 2 wherein said semiconductor material is N-type conductivity and said doped oxide is P-type conductivity.
Claim 11
Dependent Claim
24 words
forming a doped oxide layer of a second conductivity type on said undoped oxide layer and on said first selected portion of said surface,
Claim 12
Dependent Claim
24 words
forming a doped oxide layer of a second conductivity type on said undoped oxide layer and on said first selected portion of said surface,
Claim 13
Dependent Claim
25 words
removing said doped oxide layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion,
Claim 14
Dependent Claim
25 words
removing said doped oxide layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion,
Claim 15
Dependent Claim
47 words
The method of making a field effect transistor as defined by claim 3 wherein said semiconductor substrate initially has an N-type dopant concentration of about 1015 impurities per cubic centimeter and said doped oxide has a dopant concentration of between 1017 to 1019 impurities per cubic centimeter.
Claim 16
Dependent Claim
19 words
forming a second undoped oxide layer on said thin highly doped layer and on said first undoped oxide layer,
Claim 17
Dependent Claim
19 words
forming a second undoped oxide layer on said thin highly doped layer and on said first undoped oxide layer,
Claim 18
Dependent Claim
31 words
removing said second oxide layer and said thin highly doped layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion,
Claim 19
Dependent Claim
31 words
removing said second oxide layer and said thin highly doped layer from a second selected portion of said surface within said first selected portion and extending across said first selected portion,
Claim 20
Independent Claim
22 words
The method of making a field effect transistor in a doped semiconductor substrate of a first conductivity type comprising the steps of
Claim 21
Independent Claim
22 words
The method of making a field effect transistor in a doped semiconductor substrate of a first conductivity type comprising the steps of
Claim 22
Dependent Claim
43 words
forming an undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said doped oxide layer into said substrate thereby converting regions in said substrate directly beneath said doped oxide layer to the second conductivity type and
Claim 23
Dependent Claim
43 words
forming an undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said doped oxide layer into said substrate thereby converting regions in said substrate directly beneath said doped oxide layer to the second conductivity type and
Claim 24
Dependent Claim
27 words
forming source and drain electrical contacts to said regions and a gate electrical contact on said undoped oxide layer on the surface of said second selected portion.
Claim 25
Dependent Claim
27 words
forming source and drain electrical contacts to said regions and a gate electrical contact on said undoped oxide layer on the surface of said second selected portion.
Claim 26
Dependent Claim
44 words
forming a third undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said highly doped surface into said substrate thereby converting regions in said substrate directly beneath said highly doped layer to the second conductivity type, and
Claim 27
Dependent Claim
44 words
forming a third undoped oxide layer on the surface of said second selected portion, and concurrently diffusing impurities from said highly doped surface into said substrate thereby converting regions in said substrate directly beneath said highly doped layer to the second conductivity type, and
Claim 28
Dependent Claim
25 words
The method of making a field effect transistor as defined by claim 5 wherein said semiconductor material is silicon and said oxide is silicon oxide.
Claim 29
Dependent Claim
30 words
The method of making a field effect transistor as defined by claim 6 wherein said semiconductor material is N-type conductivity and said thin highly doped layer comprises boron oxide glass.
Claim 30
Dependent Claim
18 words
forming source and drain electrical contacts to said regions and a gate electrode on said third oxide layer.
Claim 31
Dependent Claim
18 words
forming source and drain electrical contacts to said regions and a gate electrode on said third oxide layer.
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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |