Claims
- 1. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer,
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer being thicker than the first polycrystalline silicon layer.
- 2. The process of producing a semiconductor device according to claim 1, wherein said thickness of the oxide film is in a range between 1 and 4 nm.
- 3. The process of producing a semiconductor device according to claim 1, wherein crystal grains of the first and second polycrystalline silicon layers have different grain sizes.
- 4. The process of producing a semiconductor device according to claim 1, wherein the first and second polycrystalline silicon layers are doped with an n-type impurity.
- 5. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer being thicker than the first polycrystalline silicon layer and having a larger average grain size than that of the first polycrystalline silicon layer.
- 6. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer being thicker than the first polycrystalline silicon layer and having a larger concentration of doped impurity than that of the first polycrystalline silicon layer.
- 7. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer having a larger concentration of doped impurity than that of the first polycrystalline silicon layer.
- 8. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer being thicker than the first polycrystalline silicon layer, having a larger average grain size than that of the first polycrystalline silicon layer, and having a larger concentration of doped impurity than that of the first polycrystalline silicon layer.
- 9. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer having a larger average grain size than that of the first polycrystalline silicon layer.
- 10. A process of producing a semiconductor device, comprising the steps of:
- forming a first polycrystalline silicon layer overlying a silicon oxide layer;
- forming an oxide film on said first polycrystalline silicon layer, said oxide film having a thickness such that tunnel current can flow therethrough; and
- forming a second polycrystalline silicon layer on said oxide film, the second polycrystalline silicon layer having a larger average grain size than that of the first polycrystalline silicon layer and having a larger concentration of doped impurity than that of the first polycrystalline silicon layer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-047730 |
Mar 1993 |
JPX |
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Parent Case Info
This application is a Divisional application of application Ser. No. 08/519,096, filed Aug. 24, 1995 now U.S. Pat. No. 5,793,097, the contents of which are incorporated herein by reference in their entirety, which application Ser. No. 08/519,096 is a Continuation application of application Ser. No. 08/207,132, filed Mar. 7, 1994 now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (9)
Number |
Date |
Country |
5552252 |
Apr 1980 |
JPX |
58-6598 |
Jan 1983 |
JPX |
58-42264 |
Mar 1983 |
JPX |
58-225648 |
Dec 1983 |
JPX |
233967 |
Feb 1990 |
JPX |
330363 |
Feb 1991 |
JPX |
3166757 |
Jul 1991 |
JPX |
4145657 |
May 1992 |
JPX |
4170064 |
Jun 1992 |
JPX |
Divisions (1)
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Number |
Date |
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Parent |
519096 |
Aug 1995 |
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Continuations (1)
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Number |
Date |
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Parent |
207132 |
Mar 1994 |
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