Patent US1454243A successfully refreshed from Google Patents.
US4045259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating diffused complementary field effect transistors
Assignee: Harris Corp
•
Filing: 1976-10-26
•
Granted: 1977-08-30
•
Expires: 1996-10-26
Abstract
Abstract In a process for fabricating complementary FETS, wherein a first insulative layer has apertures therein, a second insulative layer doped with N-type impurities is formed over the area in which an N channel device is to be formed and is diffused in a non-oxidizing atmosphere through apertures in the first insulative layer to form the source and drain of an N channel device. Immediately thereafter, an atmosphere containing a P-type impurity is introduced to deposit and diffuse P-type impurities through exposed apertures in the first insulative layer to form the source and drain of a P channel device.
Inventors
- 👤 Thomas J. Sanders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:27
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/017; H10D84/02; H10D84/03; H10D84/038; H10P; H10P32/00; H10P32/10; H10P32/12; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
In a process for fabricating complementary field effect transistors wherein source and drain apertures are provided through a first insulative layer superimposed on a substrate and each source and drain aperture are separated by a gate superimposed on said substrate, the improvement comprising: forming unselectively a second insulative layer doped with N-type impurities; selectively removing a portion of said second insulative layer to exposed apertures in which a P channel device is to be formed; diffusing said N-type impurities from said second insulative layer into said substrate in a nonoxidizing atmosphere to form an N channel device; and subsequently changing said nonoxidizing atmosphere to an atmosphere containing P-type impurities to diffuse P-type impurities through said exposed apertures to form said P channel device and further diffuse said N-type impurities.
Claim 2
Dependent Claim
129 words
In a process for fabricating complementary field effect transistors wherein source and drain apertures are provided through a first insulative layer superimposed on a substrate and each source and drain aperture are separated by a gate superimposed on said substrate, the improvement comprising: forming unselectively a second insulative layer doped with N-type impurities; selectively removing a portion of said second insulative layer to exposed apertures in which a P channel device is to be formed; diffusing said N-type impurities from said second insulative layer into said substrate in a nonoxidizing atmosphere to form an N channel device; and subsequently changing said nonoxidizing atmosphere to an atmosphere containing P-type impurities to diffuse P-type impurities through said exposed apertures to form said P channel device and further diffuse said N-type impurities.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said N-type and P-type diffusion steps are performed in sequence without intervening steps.
Claim 4
Dependent Claim
28 words
The process of claim 2 wherein said N-type and P-type diffusion steps are performed in a diffusion furnace without removing the composite structure said furnace between diffusion steps.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein said N-type impurity has a slower coefficient of diffusion in said substrate than said P-type impurity.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein said N-type impurity is arsenic and said P-type impurity is boron.
Claim 7
Dependent Claim
30 words
The process of claim 1 wherein said first N-type diffusion step is performed in a first diffusion furnace and said P-type diffusion step is performed in a second diffusion furnace.
Claim 8
Dependent Claim
121 words
In a process for fabricating complementary field effect transistors by diffusion to form the source and drain regions in a substrate, the improvement comprising: forming a masking layer on said substrate with apertures to expose the areas of said substrate in which said source and drain regions are to be formed; forming an insulative layer doped with N-type impurities over the area in which the source and drain regions of an N channel device is to be formed; diffusing in a nonoxidizing atmosphere said N-type impurities from said doped insulative layer into said substrate to form said N channel device; and immediately thereafter introducing a P-type impurity atmosphere to diffuse P-type impurities through exposed apertures to form a P channel device.
Claim 9
Dependent Claim
121 words
In a process for fabricating complementary field effect transistors by diffusion to form the source and drain regions in a substrate, the improvement comprising: forming a masking layer on said substrate with apertures to expose the areas of said substrate in which said source and drain regions are to be formed; forming an insulative layer doped with N-type impurities over the area in which the source and drain regions of an N channel device is to be formed; diffusing in a nonoxidizing atmosphere said N-type impurities from said doped insulative layer into said substrate to form said N channel device; and immediately thereafter introducing a P-type impurity atmosphere to diffuse P-type impurities through exposed apertures to form a P channel device.
Claim 10
Dependent Claim
47 words
The process of claim 7 wherein said doped insulative layer is formed by non-selectively forming said doped insulative layer on said masking layer and then removing a portion of said doped insulative layer to expose the apertures in which said P channel device is to be formed.
Claim 11
Dependent Claim
71 words
The process of claim 7 wherein said masking layer is a first insulative layer on said substrate having source and drain apertures, said doped insulative layer is a second insulative layer covering said source and drain regions and the gate of said N channel devices, and a third insulative layer is formed covering said source and drain regions and the gate of said P channel device during the final diffusion step.
Claim 12
Dependent Claim
19 words
The process of claim 7 wherein said N-type and P-type diffusion steps are performed in sequence without intervening steps.
Claim 13
Dependent Claim
29 words
The process of claim 10 wherein said N-type and P-type diffusion steps are performed in a diffusion furnace without removing the composite structure from said furnace between diffusion steps.
Claim 14
Dependent Claim
22 words
The process of claim 7 wherein said N-type impurity has a slower coefficient of diffusion in said substrate than said P-type impurity.
Claim 15
Dependent Claim
53 words
The process of claim 7 wherein said masking layer is an insulative layer on said substrate with openings to expose the area in which the N and P channel devices are to be formed and a gate on said substrate in said openings to define said apertures for said source and drain areas.
Claim 16
Dependent Claim
30 words
The process of claim 7 wherein said first N-type diffusion step is performed in a first diffusion furnace and said P-type diffusion step is performed in a second diffusion furnace.
References Cited (Backward Citations)
US3700507A
Cited
US3614829A
Cited
US3837935A
Cited
US3921283A
Cited
US3759763A
Cited
US3806371A
Cited
US3750268A
Cited
US3892609A
Cited
US3912559A
Cited
US3821781A
Cited
US3865654A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |