US3801383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for alignment of diffusion masks for semiconductors
Assignee: Hitachi Ltd
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Filing: 1972-01-26
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Granted: 1974-04-02
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Expires: 1992-01-26
Abstract
Abstract A method for manufacturing semiconductor devices which comprises the steps of, forming a first opening in an insulating film formed on a major surface of a silicon semiconductor substrate, forming a diffused region in the substrate by locally diffusing an impurity through the first opening in a non-oxidizing atmosphere, forming in the insulating film a second opening larger than the first opening and containing the first opening site by using the confines of the first opening as a positioning reference, forming a new insulating film covering the entire exposed surface of the substrate, and forming a third opening which is contained within the confines of the second opening by using the confines of the second opening as a positioning reference. In another example of the invention, after the formation of the second opening an exposed portion of the substrate surface is etched shallowly to form a hollow, the insulating film is entirely removed from the substrate surface, an insulating film covering the entire surface of the substrate is again provided, and then a third opening is formed in the last mentioned insulating film by using the step on the substrate surface as a positioning reference.
Inventors
- 👤 E Yamada
- 👤 Y Kosa
- 👤 E Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:57
CPC Classifications
H; H10; H10P; H10P95/00; H10P32/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
42 words
The method according to claim 1, further comprising the steps of forming a second diffused region in the semiconductor substrate by diffusing a second conductivity type determining impurity through said third opening, and providing an ohmic contact connected to each semiconductor region.
Claim 2
Dependent Claim
70 words
The method according to claim 1, wherein the diffusion of said first conductivity type determining impurity is carried out by first depositing an insulating film which contains said first conductivity type determining impurity over the exposed surface portion of the semiconductor substrate within said first opening, and then by heating the thus obtained combination in a nonoxidizing atmosphere to diffuse the impurity contained in the insulating film into the substrate.
Claim 3
Dependent Claim
32 words
The method according to claim 1, wherein said second opening is larger than both of said first and third openings and contains the entire site of both the first and third openings.
Claim 4
Dependent Claim
18 words
The method according to claim 1, wherein said other insulating film is provided by deposition from vapor phase.
Claim 5
Independent Claim
99 words
A method for manufacturing a semiconductor device comprising the steps of: a. forming a first opening in an insulating film formed on a semiconductor substrate; b. introducing a first conductivity type determining impurity into the semiconductor substrate through said first opening; then, c. forming in the insulating film a second opening larger than the first opening and containing the entire site of said first opening; d. covering the exposed semiconductor surface in said second opening with another insulating film; and e. forming in said another insulating film within the second opening a third opening which reaches the semiconductor surface.
Claim 6
Independent Claim
112 words
A method for manufacturing a semiconductor device comprising the steps of: forming a first opening in an insulating film formed on a semiconductor substrate; forming a shallow hollow in the exposed substrate surface of said substrate within said first opening; removing the remaining insulating film from the substrate surface; covering the substrate surface with another insulating film; forming a second opening in said another insulating film, said confines of the hollow serving as a reference for the alignment of a photolithographic mask; forming a diffused region in the semiconductor substrate, by diffusing a given conductivity type determining impurity through the second opening; and forming an electric contact connected to each semiconductor region.
Claim 7
Independent Claim
114 words
A method for manufacturing a semiconductor device comprising the steps of: forming a first opening in an insulating film formed on a semiconductor substrate; forming a shallow hollow by etching the exposed substrate surface within the opening; removing the remaining insulating film from the substrate surface; covering the substrate surface with another insulating film; forming a second opening in said other insulating film within the confines of the hollow, said confines of the hollow serving as a reference for the alignment of a photolithographic mask; forming a diffused region in the semiconductor substrate by diffusing a given conductivity type determining impurity through the second opening; and forming an electric contact to each forming region.
Claim 8
Dependent Claim
52 words
The method according to claim 8, wherein the diffusion of said given conductivity type determining impurity is carried out by first depositing an insulating film which contains said given conductivity type determining impurity on the exposed substrate surface within the opening and then by heating the resulting combination in a non-oxidizing atmosphere.
Claim 9
Dependent Claim
34 words
A method according to claim 6, wherein said step (c) includes the step of positioning a mask for forming said second opening at a prescribed position relative to the confines of said first opening.
Claim 10
Dependent Claim
34 words
A method according to claim 6, wherein said step (e) includes the step of positioning a mask for forming said third opening at a selected position relative to an edge of said second opening.
Claim 11
Dependent Claim
34 words
A method according to claim 10, wherein said step (e) includes the step of positioning a mask for forming said third opening at a selected position relative to an edge of said second opening.
Claim 12
Independent Claim
183 words
A method for manufacturing a semiconductor device comprising the successive steps of: a. forming a firsT opening in a first insulating film formed on a semiconductor substrate of a first conductivity type, so as to expose a first surface portion of said substrate; b. introducing a second conductivity type determining impurity into said first surface portion of said semiconductor substrate; c. forming in said first insulating film, a second opening, which exposes at least a portion of said first surface portion of said substrate and a second surface portion of said substrate, previously covered by said first insulating film, adjacent to and contiguous with said first surface portion, an edge of said first insulating film defining an edge of said second opening and being spaced apart from said first surface portion of said substrate by said second surface portion thereof; d. covering the surface of said substrate exposed by said second opening with a second insulating film; and e. forming, in said second insulating film, a third opening which extends to the surface of said substrate to expose a third surface portion thereof.
Claim 13
Dependent Claim
34 words
A method according to claim 13, wherein said step (c) includes the step of positioning a mask for forming said second opening at a prescribed position relative to the confines of said first opening.
Claim 14
Dependent Claim
34 words
A method according to claim 13, wherein said step (e) includes the step of positioning a mask for forming said third opening at a selected position relative to an edge of said second opening.
Claim 15
Dependent Claim
34 words
A method according to claim 14, wherein said step (e) includes the step of positioning a mask for forming said third opening at a selected position relative to an edge of said second opening.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |