Claims
- 1. A method for manufacturing an optically triggered lateral thyristor having a junction protecting region, guard ring and field plates, said method comprising:
- forming a first insulating layer on a surface of a semiconductor substrate of a first conductivity type;
- forming a first opening through said first insulating layer;
- forming an anode region by injecting and diffusing an impurity material of a second conductivity type opposite to said first conductivity type through said first opening into the substrate;
- forming second, third and fourth openings through said first insulating layer at positions respectively spaced from said anode region;
- forming a diffusion layer, said junction protecting region and said guard ring by injecting and diffusing an impurity of said second conductivity type through said second, third and fourth openings into the substrate;
- forming a fifth opening through said first insulating layer at a position between said second and third openings and externally adjacent to said second opening;
- forming a second conductivity type region by injecting and diffusing an impurity of said second conductivity type through said fifth opening into the substrate;
- injecting an impurity of said first conductivity type through said fifth opening into said second conductivity type region;
- performing a double diffusion step wherein base and cathode diffusions are performed through said fifth opening, in the absence of an intervening masking step, for transforming said second conductivity type region made through said fifth opening into a base region and transforming said first conductivity type impurity injected through said fifth opening into a cathode region, said base and cathode regions being transformed with a difference in their diffusion length which realizing stably the minimum lateral width of the base region for reducing the forward voltage drop of the thyristor;
- forming on said first insulating layer conducting layers at positions cooperable with said guard ring;
- forming a second insulating layer over said first insulating layer and conducting layers; and
- forming on said second insulating layer anode, base and cathode electrodes in contact respectively with said anode, base and cathode regions through said first and second insulating layers, said anode and cathode electrodes respectively being in contact also with respective conducting layers to form said field plates.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2-43331 |
Feb 1990 |
JPX |
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2-43332 |
Feb 1990 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 08/020,466, filed Feb. 22, 1993, which is a continuation of application Ser. No. 07/656,947, filed Feb. 19, 1991 both now abandoned.
US Referenced Citations (14)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0159883 |
Dec 1979 |
JPX |
63-7471 |
Jan 1988 |
JPX |
2133641 |
Jul 1984 |
GBX |
2150348 |
Jun 1985 |
GBX |
3808579 |
Oct 1988 |
GBX |
Non-Patent Literature Citations (2)
Entry |
P. D. Taylor, "Thyristor Design and Realization," Design and Measurement in Electrical and Electronic Engineering, by John Wiley & Sons, cover sheet and pp. 62-63, 1987. |
Article, "Electronics", Nikkei Electronics dated Dec. 10, 1979/p. 197 et seq. |
Continuations (2)
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Number |
Date |
Country |
Parent |
20466 |
Feb 1993 |
|
Parent |
656947 |
Feb 1991 |
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