Patent EP0263504A2 successfully refreshed from Google Patents.
EP0263504A2
Expired / Lapsed
EP
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Method for manufacturing high-breakdown voltage semiconductor device
Assignee: Toshiba Corp
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Filing: 1987-10-07
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Granted: —
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Expires: 2007-10-07
Abstract
Abstract A first silicon oxide film (11) is formed on the major surface of an n-type silicon substrate (10). A silicon nitride film is formed on the first silicon oxide film. The first silicon oxide film and the silicon nitride film are selectively etched to form an opening. Boron ions are implanted into the silicon substrate (10) using the first silicon oxide film (11) and the silicon nitride film as a mask. A second silicon oxide film (16) is formed on the silicon substrate (10) exposed by the opening. Gallium ions are implanted into the second silicon oxide film (16) using the silicon nitride film as a mask. Boron and gallium ions are simultaneously diffused in the silicon substrate. In this case, a diffusion rate of gallium in the silicon substrate is higher than that of boron in the silicon substrate (10), and the diffusion rate of gallium in the silicon oxide film (11) is higher than that in the silicon substrate (10). Therefore, a p-type second layer is formed in the substrate to surround a p⁺-type first layer in a self-aligned manner.
Inventors
- 👤 Yutaka C/O Patent Division Koshino
- 👤 Yoshiro C/O Patent Division Baba
- 👤 Jiro C/O Patent Division Ohshima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 10:10
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/061; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D62/17; H10D62/177; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1404; H10P32/1406; H10P32/17; H10P32/171; H10P76/00; H10P76/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
253 words
A method for manufacturing a semiconductor device comprising the step of forming a first layer in a silicon substrate of a first conductivity type and the step of forming a second layer of a second conductivity type to surround said first layer, characterized in that the step of forming said first layer and the step of forming said second layer comprise steps of: forming a first silicon oxide film (11) on a major surface of a silicon substrate (10) of the first conductivity type; selectively etching said first silicon oxide film (11) to form an opening (14); forming a second silicon oxide film (16) on said silicon substrate (10) through said opening (14); doping, before or after the step of forming said second silicon oxide film, doping a first impurity in a portion of said silicon substrate (10) opposing said opening (14) using said first silicon oxide film (11) as a mask; doping, into said second silicon oxide film (16), a second impurity of the second conductivity type, a diffusion rate of which in said silicon substrate (10) is higher than that of said first impurity in said silicon substrate (10), and a diffusion rate of which in said first silicon oxide film (11) is higher than that in said silicon substrate (10); and diffusing said first impurity and said second impurity of the second conductivity type into said silicon substrate to form, in said silicon substrate, said first layer and said second layer of the second conductivity type surrounding said first layer.
Claim 2
Independent Claim
253 words
A method for manufacturing a semiconductor device comprising the step of forming a first layer in a silicon substrate of a first conductivity type and the step of forming a second layer of a second conductivity type to surround said first layer, characterized in that the step of forming said first layer and the step of forming said second layer comprise steps of: forming a first silicon oxide film (11) on a major surface of a silicon substrate (10) of the first conductivity type; selectively etching said first silicon oxide film (11) to form an opening (14); forming a second silicon oxide film (16) on said silicon substrate (10) through said opening (14); doping, before or after the step of forming said second silicon oxide film, doping a first impurity in a portion of said silicon substrate (10) opposing said opening (14) using said first silicon oxide film (11) as a mask; doping, into said second silicon oxide film (16), a second impurity of the second conductivity type, a diffusion rate of which in said silicon substrate (10) is higher than that of said first impurity in said silicon substrate (10), and a diffusion rate of which in said first silicon oxide film (11) is higher than that in said silicon substrate (10); and diffusing said first impurity and said second impurity of the second conductivity type into said silicon substrate to form, in said silicon substrate, said first layer and said second layer of the second conductivity type surrounding said first layer.
Claim 3
Dependent Claim
22 words
A method according to claim 1, characterized in that said first impurity comprises at least one of boron (B) and arsenic (As).
Claim 4
Dependent Claim
22 words
A method according to claim 1, characterized in that said second impurity comprises at least one of gallium (Ga) and aluminum (Aℓ).
Claim 5
Dependent Claim
44 words
A method according to claim 1, characterized in that at least one of the step of doping said first impurity into said silicon substrate (10) and the stepof doping said second impurity into said second silicon oxide film (16) comprises a step of ion-implantation.
Claim 6
Dependent Claim
96 words
A method according to claim 1, characterized in that said method further has a step of forming, on said first silicon oxide film, an insulating film in which a diffusion rate of said second impurity is lower than that of said second impurity in said silicon oxide film, the step of forming said opening (14) comprises a step of etching said first silicon oxide film and said insulating film, and the step of doping said second impurity comprises a step of doping said second impurity into said second silicon oxide film (16) and said insulating film.
Claim 7
Dependent Claim
28 words
A method according to claim 5, characterized in that said insulating film comprises at least one of a silicon nitride (SiN₃) film and a silicon carbide (SiC) film.
Claim 8
Dependent Claim
50 words
A method according to claim 1, characterized in that said first impurity comprises boron (B), said second impurity comprises at least one of gallium (As) and aluminum (Aℓ), and said method further comprises a step of forming a region (19) of the first conductivity type in said first layer (15a).
Claim 9
Dependent Claim
144 words
A method according to claim 1, characterized in that the step of forming said first silicon oxide film further comprises a step of forming an insulating film comprising at least one of a silicon nitride film and a silicon carbide film (12) on said first silicon oxide film (11), the step of forming said second silicon oxide film (16) comprises a step of forming a silicon oxide film having a smaller thickness than that of said first silicon oxide film, the step of doping said first impurity comprises a step of ion-implanting said first impurity into said silicon substrate using said first silicon oxide film (11) and said insulating film (12) as a mask, and the step of doping said second impurity comprises a step of ion-implanting said second impurity into said second silicon oxide film (16) using said insulating film as a mask.
Claim 10
Independent Claim
178 words
A method for manufacturing a semiconductor device, comprising: a step of forming an insulating film (11, 16) on one major surface of a semiconductor substrate (10); a step, performed at least one of before and after the step of forming said insulating film (11, 16), of doping a first impurity (15) into a predetermined surface region of said substrate (10); a step of ion-implanting, into a portion (16) of said insulating film (11, 16) facing to said predetermined surface region, a second impurity, a diffusion rate of which in said semiconductor substrate (10) is higher than that of said first impurity (15) in said semiconductor substrate (10), and a diffusion rate of which in said insulating film (11, 16) is higher than that in said semiconductor substrate (10); and a step of diffusing said first impurity (15) and said second impurity of the second conductivity type to form, in a surface region of said semiconductor substrate, a first layer (15a) containing said first impurity and a second layer (18a) containing said second impurity and surrounding said first layer.
Claim 11
Independent Claim
178 words
A method for manufacturing a semiconductor device, comprising: a step of forming an insulating film (11, 16) on one major surface of a semiconductor substrate (10); a step, performed at least one of before and after the step of forming said insulating film (11, 16), of doping a first impurity (15) into a predetermined surface region of said substrate (10); a step of ion-implanting, into a portion (16) of said insulating film (11, 16) facing to said predetermined surface region, a second impurity, a diffusion rate of which in said semiconductor substrate (10) is higher than that of said first impurity (15) in said semiconductor substrate (10), and a diffusion rate of which in said insulating film (11, 16) is higher than that in said semiconductor substrate (10); and a step of diffusing said first impurity (15) and said second impurity of the second conductivity type to form, in a surface region of said semiconductor substrate, a first layer (15a) containing said first impurity and a second layer (18a) containing said second impurity and surrounding said first layer.
Claim 12
Dependent Claim
156 words
A method according to claim 9, characterized in that the step of forming said insulating film comprises: a step of forming a first silicon oxide film (11) on a major surface of a silicon substrate (10) of the first conductivity type; a step of selectively etching said first silicon oxide film (11) to form an opening (14); and a step of forming a second silicon oxide film (16) on said silicon substrate (10) through said opening (14), the step of doping said first impurity comprises a step, performed at least one of before and after the step of forming said second silicon oxide film (16), of doping said first impurity (15) into a portion of said silicon substrate (10) opposing said opening (14) using said first silicon oxide film (11) as a mask, and the step of doping said second impurity comprises a step of doping said second impurity into said second silicon oxide film (16).
References Cited (Backward Citations)
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