EP0091624A2
Expired / Lapsed
EP
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Method of manufacturing vertical semiconductor devices
Assignee: Nissan Motor Co Ltd
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Filing: 1983-03-31
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Granted: —
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Expires: 2003-03-31
Abstract
Abstract A method of manufacturing a vertical semiconductor device including a plurality of parallel-connected transistors comprises an anodizing step, before the electrodes (28, 29) are formed, in addition to the conventional manufacturing steps. Since defective semiconductor regions due to short circuit, poor withstand voltage or pin holes (PH) are insulated from the corresponding electrodes by an insulating material (27) formed in the anodizing step, even if any of parallel-connected transistors are defective, the integrated circuit is usable, thus reducing the percentage of defectiveness of the vertical semiconductor devices in the assembly line.
Inventors
- 👤 Koichi Murakami
- 👤 Teruyoshi Mihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 14:05
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/133; H10D62/135
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
88 words
A method of manufacturing a vertical semiconductor device including a plurality of parallel-connected semiconductor elements, each of which is formed in a substrate (2) including at-least one semiconductor region and provided with at-least one electrode connected to the semiconductor region characterized in a step of anodizing the substrate (2) with the substrate as an anode, after the step of etching an insulating film (1;25) formed on the substrate into at-least one predetermined common electrode pattern but before forming at-least one common electrode (11;28) connected to each semiconductor region.
Claim 2
Independent Claim
88 words
A method of manufacturing a vertical semiconductor device including a plurality of parallel-connected semiconductor elements, each of which is formed in a substrate (2) including at-least one semiconductor region and provided with at-least one electrode connected to the semiconductor region characterized in a step of anodizing the substrate (2) with the substrate as an anode, after the step of etching an insulating film (1;25) formed on the substrate into at-least one predetermined common electrode pattern but before forming at-least one common electrode (11;28) connected to each semiconductor region.
Claim 3
Dependent Claim
62 words
A method of manufacturing a vertical semiconductor device as set forth in claim 1, characterized (9) in a step of forming a metal film on each semiconductor region, after the step of etching an insulating film (1;25) formed on each substrate into at-least one predetermined common electrode pattern but before said step of anodizing the substrate with the substrate as an anode.
Claim 4
Dependent Claim
51 words
A method of manufacturing a vertical semiconductor device as set forth in either claim 1 or 2, characterized in a step of etching the substrate (2) to remove an anodized film formed in the step of anodizing the substrate, before forming at-least one common electrode (11;28) connected to each semiconductor region(5,6;23).
Claim 5
Dependent Claim
37 words
A method as set forth in claim 1, characterized in that the anode voltage (V A ) applied to the substrate (2) is a little lower than the maximum allowable voltage between the substrate and the electrode.
Claim 6
Independent Claim
45 words
A method as claimed in one the claims 3 or 4 and 2, characterized in that said metal film (9) is an aluminum film with a thickness of about 0.5 to 1 micron, said aluminum being anodized into aluminum oxide during said step of anodizing.
Claim 7
Independent Claim
215 words
A method as claimed in one of the preceeding claims, characterized in that said semiconductor device includes a plurality of parallel-connected MOS transistors, said method comprising the following steps of: (a) forming a first silicon oxide gate film (1) on the surface of a N-type semiconductor drain substrate (2); (b) forming a poly-silicon gate electrode film (3) on the first silicon oxide gate film (1); (c) etching the poly-silicon gate electrode film into a predetermined gate electrode pattern and the first silicon oxide film into a predetermined source region pattern; (d) forming p-type wells (4), N +- type source regions (5) and p +- type isolation regions (6) on the exposed N-type semiconductor drain substrate (2) to provide a plurality of source regions; (7) (e) forming a second silicon oxide insulating film (7) on the substrate; (f) etching the second silicon oxide insulating film (7) into a predetermined source region pattern; (g) anodizing the substrate with the substrate as an anode; (h) forming an aluminum conductive film (11) on the substrate; and (i) etching the aluminum conductive film into a predetermined common source electrode connected to a plurality of the source regions, (Def) whereby only defective source regions are anodized into silicon oxide for insulating the defective source regions from the aluminum common source electrode.
Claim 8
Dependent Claim
80 words
A method of manufacturing a vertical semiconductor as set forth in claim 6, characterized in the step of forming an aluminum conductive film(9) on each source region, after the step of etching the second silicon oxide insulating film (7) into a predetermined source region pattern but before the step of anodizing the substrate, whereby only aluminum conductive films on (Def) defective source regions are anodized into aluminum oxide(10) for insulating the defective source regions from the aluminum common source electrode(11).
Claim 9
Dependent Claim
85 words
A method of manufacturing a vertical semiconductor device as set forth in claim 1, characterized in the following steps of: (a) anodizing the substrate with the substrate(2) as an anode, after the step of etching .a poly-silicon (3) gate electrode film into a predetermined gate electrode pattern; and (b) further forming another poly-silicon gate electrode film (3') on the anodized substrate, whereby only defective poly-silicon gate electrodes are anodized into silicon oxide for insulating the gate electrode from the drain substrate ( F ig. 6).
Claim 10
Dependent Claim
53 words
A method of manufacturing a vertical semiconductor device as set forth in any of claim 6, 7 or 8, characterized in the step of etching the substrate to remove an anodized film formed in the step of anodizing the substrate, before the step of forming the aluminum conductive film (11) on the substrate.
Claim 11
Dependent Claim
169 words
A method as claimed in claim 1, characterized in that said semiconductor device includes. a plurality of parallel-connected bi-polar transistors, said method comprising the following steps of: (a) forming a P -type region (21) on the surface of a N-type semiconductor collector substrate (22); (23) (b) forming N +- type emitter regions and P -type (24) . base regions on the P-type region; (25) (c) forming a silicon oxide film' on the substrate; (25) (d) etching the silicon oxide film' into a predetermined emitter electrode pattern and a predetermined base electrode pattern; (e) anodizing the substrate with the substrate as an anode; (f) forming an aluminum conductive film on the substrate; and (g) etching the aluminum conductive film into a (28) predetermined common emitter electrode connected to a plurality of the emitter regions and into a predetermined (29) common base electrode connected to a plurality of the base regions, whereby only defective emitter regions are anodized into silicon oxide for insulating the defective emitter from the common emitter electrode.
Claim 12
Dependent Claim
86 words
ll. A me.thod as claimed in any one of the claims 1-5,or in claim.10, characterized in the step of forming an aluminum (26) (23) (24) conductive film on each emitter and base region, after the step of etching the silicon oxide film (25) into a predetermined emitter region pattern and a predetermined base region pattern but before the step of anodizing the substrate, whereby only aluminum conductive films on defective emitter are anodized into aluminum oxide for insulating the defective emitter from the common emitter electrode.
Claim 13
Dependent Claim
52 words
A method of manufacturing a vertical semiconductor device as set forth in either claim 10 or 11, which further comprises the step of etching the substrate to remove the anodized film formed in the step of anodizing the substrate, before the step of forming the aluminum conductive fi m on the substrate.
References Cited (Backward Citations)
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