Claims
- 1. A method of preparing a silicon dioxide film perforated in a prescribed pattern, the film to be used as a mask on the surface of semiconductor material for manufacture of a dimensionally precise semiconductor device, the method comprising:
- (a) forming a silicon dioxide film substantially covering the surface of the semiconductor material;
- (b) adheringly covering said silicon dioxide film with a silicon carbide mask comprising a silicon carbide film perforated in the prescribed pattern wherein the silicon carbide mask is formed by a "lift off" process with the prescribed perforated pattern;
- (c) selectively etching said silicon dioxide film using hydrofluoric acid or ammonium fluoride through the perforations having the prescribed pattern in said silicon carbide mask, thereby providing a dimensionally precise silicon dioxide mask for diffusion of an impurity or deposition of an electrode.
- 2. The method as in claim 1 wherein said "lift off" process includes the sub-steps of
- (i) forming a photoresist film on said silicon dioxide layer, said photoresist film being perforated in the prescribed pattern to expose portions of said silicon dioxide layer,
- (ii) depositing a layer of silicon carbide over said photoresist film and said exposed silicon dioxide layer portions, and
- (iii) removing said photoresist film together with the part of said silicon carbide layer overlying said photoresist film.
- 3. The method as in claim 2 wherein the thickness of said silicon carbide layer is less than the thickness of said photoresist film, and wherein said photoresist film and overlying silicon carbide layer part are removed using a solvent.
Priority Claims (3)
Number |
Date |
Country |
Kind |
51-102430 |
Aug 1976 |
JPX |
|
51-127808 |
Oct 1976 |
JPX |
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51-127809 |
Oct 1976 |
JPX |
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BACKGROUND OF THE INVENTION
This is a continuation of Ser. No. 403,550, filed July 30, 1982, now abandoned which was a division of application Ser. No. 262,938, filed May 12, 1981 (now U.S. Pat. No. 4,351,894 issued Sept. 28, 1982) which was a continuation of application Ser. No. 047,216, filed June 11, 1979 (abandoned), which was a continuation of application Ser. No. 827,347, filed Aug. 24, 1977 (abandoned).
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3465209 |
Denning et al. |
Sep 1969 |
|
3502517 |
Sussmann |
Mar 1970 |
|
3904454 |
Hagdo et al. |
Sep 1975 |
|
Foreign Referenced Citations (8)
Number |
Date |
Country |
1589830 |
Aug 1970 |
DEX |
1475359 |
Feb 1967 |
FRX |
1530218 |
May 1968 |
FRX |
1093567 |
Dec 1967 |
GBX |
1142405 |
Feb 1969 |
GBX |
1147014 |
Apr 1969 |
GBX |
1188152 |
Apr 1970 |
GBX |
1319079 |
May 1973 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Bersin, Solid State Technology, 5/76, pp. 31-36. |
Weaver, JBM Technical Disclosure Bulletin, vol. 17, No. 2, 7/74. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
262938 |
May 1981 |
|
Continuations (3)
|
Number |
Date |
Country |
Parent |
403550 |
Jul 1982 |
|
Parent |
047216 |
Jun 1979 |
|
Parent |
827347 |
Aug 1977 |
|