Claims
- 1. A method of manufacturing a static induction type switching device comprising the steps of:
- (a) preparing a first conductivity type semiconductor substrate having top and bottom major surfaces;
- (b) forming a first conductivity type region on said top major surface of said semiconductor substrate;
- (c) selectively removing said first conductivity type region and said semiconductor substrate to thereby define trenches which are arrayed substantially in parallel with said top major surface;
- (d) forming polysilicon regions containing second conductivity type impurities in bottom portions of said trenches by providing a material substantially made of polysilicon having a second conductivity impurities into said trenches and removing a top portion of said material from each of said trenches to thereby obtain polysilicon regions;
- (e) diffusing said second conductivity type impurities from said polysilicon regions serving as diffusion sources to thereby form diffused regions on peripheries of said polysilicon regions, said diffused regions serving as gate regions with said polysilicon regions; and
- (f) forming a first or second conductivity type second main electrode region on said bottom major surface of said semiconductor substrate.
Priority Claims (1)
Number |
Date |
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1-9014 |
Jan 1989 |
JPX |
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Parent Case Info
This application is a continuation application of U.S. patent application Ser. No. 07/518,300 and which was filed on May 2, 1990 now U.S. Pat. No. 5,143,859. U.S. patent application Ser. No. 07/518,300 is a divisional application filed under the provisions of 37 CFR .sctn.1.62 of U.S. patent application Ser. No. 07/356,054 filed May 23, 1989 now abandoned.
US Referenced Citations (20)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0018751 |
Jan 1987 |
JPX |
0104464 |
May 1988 |
JPX |
0169759 |
Jul 1988 |
JPX |
0147481 |
Dec 1988 |
JPX |
2026237 |
Jan 1980 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Nishizawa et al., "Field-Effect Transistor Versus Analog Transistor (Static Induction Transistor)"; IEEE Transactions on Electron Devices, vol. ED-22, No. 4, Apr. 1975. |
Wessels et al., "Vertical Channel Field--Controlled Thyristors With High Gain and Fast Switching Speeds"; IEEE Transaction on Electron Devices, vol. ED-25; No. 10, Oct. 1978. |
Divisions (1)
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Number |
Date |
Country |
Parent |
356054 |
May 1989 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
518300 |
May 1990 |
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