US3765963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing semiconductor devices
Assignee: Fujitsu Ltd
•
Filing: 1971-03-24
•
Granted: 1973-10-16
•
Expires: 1991-03-24
Abstract
Abstract A method of manufacturing semiconductor devices comprises the steps of covering the surface of a semiconductor substrate with an insulating film, leaving a designated surface portion uncovered and exposed. A silica glass film containing an impurity is formed on top of the insulating film and on the said surface portion. Thereafter, the substrate is heated to diffuse the impurity from the glass film into the semiconductor substrate, forming a transmuted layer whose saturated concentration is lower than the concentration of the impurity contained in the glass film and which transmuted layer has an etching rate lower than that of the glass film. After the etching step the glass film is removed from the transmuted layer and from said surface portion by chemical etching.
Inventors
- 👤 T Okabe
- 👤 E Tanikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:15
CPC Classifications
H; H10; H10P; H10P95/00; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6923; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; H10W; H10W74/00; H10W74/40
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
175 words
A method of manufacturing semiconductor devices comprising the steps of a. opening a base window in a diffusion mask provided on a semiconductor substrate for protecting the substrate surface, at least the surface zone of said semiconductor substrate being of N type; b. forming a borosilicate glass film on at least said base window; c. heating said semiconductor substrate to diffuse boron from said borosilicate glass film into said semiconductor substrate; d. opening an emitter window in said borosilicate glass film formed within said base window; e. forming a phosphosilicate glass layer on the surface of said semiconductor substrate; f. performing a diffusion treatment by heating to form a transmuted layer having a saturated concentration of phosphorus lower than the concentration of phosphorus in said phosphosilicate glass layer on the inTerface between said phosphosilicate glass layer and said diffusion mask; and g. dipping said semiconductor substrate in an etching liquid to remove said phosphosilicate glass layer containing phosphorus at a higher concentration, leaving said phosphorus-containing transmuted layer on the upper surface of said semiconductor substrate.
Claim 2
Dependent Claim
13 words
The method of claim 2 wherein said diffusion mask consists of silicon dioxide.
Claim 3
Dependent Claim
24 words
The method of claim 2 wherein said diffusion treatment is performed at a temperature exceeding 1000* C but lower than the semiconductor melting temperature.
Claim 4
Dependent Claim
26 words
A method according to claim 2, wherein said phosphorus containing transmuted layer is left on the side walls of the emitter window in said borosilicate film.
Claim 5
Independent Claim
185 words
A method of manufacturing semiconductor devices comprising the steps of a. opening a base window in a diffusion mask provided on a semiconductor substrate and protecting the surface of said semiconductor substrate, at least the surface zone of said semiconductor substrate being of N type; b. depositing boron onto the semiconductor substrate through said base window; c. heating said substrate in an oxidizing atmosphere to diffuse boron into the interior of the substrate; d. forming a diffusion mask on the surface of the base; e. forming an emitter window in said diffusion mask formed within said base window; f. forming a phosphosilicate glass layer on the surface of said substrate; g. performing an emitter diffusion treatment by heating to form a transmuted layer having a saturated concentration of phosphorus lower than the concentration of phosphorus in said phosphosilicate glass layer on the interface between said phosphosilicate glass layer and said diffusion mask; and h. dipping said substrate in an etching liquid to remove said phosphosilicate glass layer containing phosphorus at a higher concentration, leaving said phosphorus-containing transmuted layer on the upper surface of said substrate.
Claim 6
Dependent Claim
13 words
The method of claim 6 wherein said diffusion mask consists of silicon dioxide.
Claim 7
Dependent Claim
25 words
The method of claim 6 wherein said emitter diffusion treatment is performed at a temperature exceeding 1000* C but lower than the semiconductor melting temperature.
Claim 8
Dependent Claim
26 words
A method according to claim 6, wherein said phosphorus containing transmuted layer is left on the side walls of the emitter window in said diffusion mask.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |