US5021839A
Expired / Lapsed
US
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FET with a super lattice channel
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1989-04-25
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Granted: 1991-06-04
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Expires: 2009-04-25
Abstract
Abstract An improved FET is disclosed. The transistor is characterized in that its channel is constituted in the form of a super lattice. The super lattice structure provides a number of square well potential areas through which carriers can pass with little interaction with the gate insulating film.
Inventors
- 👤 Shunpei Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:27
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/81; H10D62/815; H10D62/8161; H10D62/8162; H10D30/00; H10D30/60; H10D30/601; H10D30/751; Y; Y10; Y10S; Y10S148/00; Y10S148/09; Y10S148/091; Y10S148/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
72 words
An insulated-gate field effect transistor comprising: a substrate within which a source a drain region is formed; a superlattice structure as a channel region placed between said source and drain region, said superlattice structure including alternating crystalline silicon semiconductor and silicon compound layers; and an insulating layer formed on said superlattice structure, where said substrate includes a bulk portion in contact with the superlattice structure, said bulk portion being single crystalline semiconductor.
Claim 2
Dependent Claim
72 words
An insulated-gate field effect transistor comprising: a substrate within which a source a drain region is formed; a superlattice structure as a channel region placed between said source and drain region, said superlattice structure including alternating crystalline silicon semiconductor and silicon compound layers; and an insulating layer formed on said superlattice structure, where said substrate includes a bulk portion in contact with the superlattice structure, said bulk portion being single crystalline semiconductor.
Claim 3
Dependent Claim
24 words
A device as in claim 1 where the energy bandgaps of said crystalline silicon semiconductor layers and said bulk portion are substantially the same.
Claim 4
Dependent Claim
29 words
A device as in claim 1 where the thickness of said crystalline silicon semiconductor layers is 5 to 100Å and the thickness of the silicon compound layers is 10-100Å.
Claim 5
Dependent Claim
14 words
A device as in claim 1 wherein said silicon compound layers comprise silicon nitride.
Claim 6
Dependent Claim
30 words
A device as in claim 4 wherein the thickness of said crystalline silicon semiconductor layers is 5 to 100 Å and the thickness of the silicon nitride layers is 10-100Å.
Claim 7
Dependent Claim
15 words
A device as in claim 1 where said silicon compound layers comprise SiO 2-x (0<x<2).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |