US3833429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a semiconductor device
Assignee: Fujitsu Ltd
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Filing: 1972-11-28
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Granted: 1974-09-03
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Expires: 1992-11-28
Abstract
Abstract A high speed bipolar transistor with a small base area is produced by silicon nitride double films formed on a silicon substrate. The upper nitride film has a window for base diffusion and the lower nitride film has a window for emitter diffusion which overlaps the base diffusion window. The emitter diffusion occurs only in the overlapped portion of the base diffusion window and the emitter diffusion window. The diffusion source used for emitter diffusion is removed by using the nitride film as a mask.
Inventors
- 👤 Y Monma
- 👤 S Abe
- 👤 R Miwa
- 👤 E Mitsushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:40
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0112; H10D84/02; H10D84/03; H10D84/038; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/085; Y10S148/106
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
19 words
A method as claimed in claim 1, wherein each of the first and second insulation films comprises silicon nitride.
Claim 2
Dependent Claim
19 words
A method as claimed in claim 1, wherein each of the first and second insulation films comprises aluminum oxide.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1, further comprising the step of diffusing impurities through the third window.
Claim 4
Dependent Claim
25 words
A method as claimed in claim 1, further comprising the step of providing electrical contacts on the surface of the silicon in the third window.
Claim 5
Independent Claim
114 words
A method of manufacturing a semiconductor device, comprising the steps of forming a first insulation film having a first window on a silicon semiconductor substrate; diffusing first impurities through the first window; forming a silicon oxide film on the surface of the silicon in the first window; forming a second insulatin layer having a seCond window which partially overlaps the first window and extends over the first insulation film; selectively removing the silicon oxide film exposed in the overlapped portion of the first and second windows by using the first and second insulation films as masks and forming a third window in the silicon oxide film; and diffusing second impurities through the third window.
Claim 6
Dependent Claim
18 words
A method as claimed in claim 6, wherein each of the first and second films comprises silicon nitride.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 6, wherein each of the first and second films comprises aluminum oxide.
Claim 8
Dependent Claim
25 words
A method as claimed in claim 6, further comprising the steps of providing electrical contacts on the surface of the silicon in the third window.
Claim 9
Dependent Claim
67 words
A method as claimed in claim 6, further comprising the steps of forming a silicon oxide film on the surface of the silicon in the third window during the diffusion of the second impurities, selectively removing the silicon oxide film in the third window using the first and second insulation films as masks, and providing electrical contacts on the surface of the silicon in the third window.
Claim 10
Independent Claim
153 words
A method of manufacturing a transistor, comprising the steps of forming a first insulation film having a base window on a silicon semiconductor substrate having a surface layer of one conductivity type; forming a base by diffusing impurities of the opposite conductivity type to that of the surface layer through the base window; forming a silicon oxide film on the silicon surface in the base window; forming a second insulation film having a window for emitter formation which partially overlaps the base window and extends over the first insulation film; selectively removing the silicon oxide film exposed in the overlapped portion of the base window and the window for emitter formation by using the first and second insulation films as masks and forming an emitter window in the silicon oxide film; and forming the emitter by diffusing impurities of the same conductivity type as that of the surface layer through the emitter window.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 11, wherein each of the first and second insulation films comprises silicon nitride.
Claim 12
Dependent Claim
18 words
A method as claimed in claim 11, wherein each of the first and second films comprises silicon aluminum.
Claim 13
Dependent Claim
71 words
A method as claimed in claim 11, further comprising the steps of forming a silicon oxide film on the surface of the silicon in the emitter window during the emitter formation, providing an emitter contact window by selectively removing the silicon oxide film in the emitter window, using the first and second insulation films as masks, and providing an emitter electrode contact on the emitter surface in the emitter contact window.
Claim 14
Dependent Claim
31 words
A method as claimed in claim 11, further comprising the step of providing a window for base electrode formation adjacent to the window for emitter formation in the second insulation film.
Claim 15
Dependent Claim
130 words
A method as claimed in claim 11, further comprising the steps of providing a window for base electrode formation adjacent to the window for emitter formation in the second insulation film, forming a silicon oxide film on the surface of the silicon in the emitter window during emitter formation, selectively removing the silicon oxide film in the emitter window by using the first and second insulation films as masks to provide an emitter contact window, providing an emitter electrode contact on the emitter surface in the emitter contact window, selectively removing the silicon oxide film in the base window by using the first and second insulation films as masks to provide a base contact window, and providing a base electrode contact on the base surface in the base contact window.
Claim 16
Independent Claim
108 words
A method of manufacturing an integrated circuit, comprising the steps of providing a buried diffusion region in a silicon epitaxial substrate; forming a silicon oxide film on one surface of the epitaxial substrate; forming a firSt insulation film having a base window; forming an isolation diffusion window surrounding the base window; selectively removing the silicon oxide film in the isolation diffusion window by using the first insulation film as a mask; providing isolation diffusion through the isolation diffusion window; removing the silicon oxide film in the base window by using the first insulation film as a mask; and forming a base by diffusing impurities through the base window.
Claim 17
Dependent Claim
78 words
A method as claimed in claim 17, further comprising the steps of forming a second insulation film having a window for emitter formation which partially overlaps the base window and extends over the first insulation film, selectively removing the silicon oxide film exposed in the overlapped portion of the base window and the window for emitter formation to form an emitter window in the silicon oxide film, and forming an emitter by diffusing impurities through the emitter window.
Claim 18
Dependent Claim
23 words
A method as claimed in claim 17, further comprising the step of providing a collector contact diffusion window in the first insulation film.
Claim 19
Dependent Claim
27 words
A method as claimed in claim 17, further comprising the steps of providing a window for resistor diffusion in another island portion of the first insulation film.
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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |