US4277882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a metal-semiconductor field-effect transistor
Assignee: National Semiconductor Corp
•
Filing: 1978-12-04
•
Granted: 1981-07-14
•
Expires: 1998-12-04
Abstract
Abstract A metal-semiconductor field-effect transistor is formed by providing a blanket layer of the same conductivity type as the semiconductor body, with field oxide subsequently being grown, and with a region of opposite conductivity type being formed to extend partially under the field oxide, the initial blanket layer acting as the field implant region of the field-effect transistor.
Inventors
- 👤 Peter A. Crossley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:43
CPC Classifications
H; H10; H10P; H10P34/00; H10D; H10D30/00; H10D30/80; H10D30/87; H10P14/00; H10P14/60; H10P14/61; H10P76/00; H10P76/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
239 words
A method of producing a Schottky-barrier, field-effect transistor comprising: providing a semiconductor body of one conductivity type and a low impurity concentration; forming an ion implantation layer of said one conductivity type through the surface of said body, said ion implantation layer having a higher impurity concentration than said semiconductor body; oxidizing said surface of the body to provide an electrically insulating oxide layer portion of said body over the ion implantation layer; masking an area of said insulating oxide layer wherein said area is surrounded by an exposed portion thereof; oxidizing the body again at a high temperature to increase the thickness of the exposed portion of said insulating oxide layer to form a field oxide layer; removing the mask and said thin oxide thereunder to expose a region of higher impurity beneath the area previously covered by the mask; forming a region of opposite conductivity type opposite to said one conductivity type in said body in the exposed region and extending the region of opposite conductivity type under a portion of oxide layer and into the semiconductor body beneath the ion implantation layer; providing a conductive gate forming a Schottky junction with an exposed portion of the region of opposite conductivity type and extending over the field oxide layer but not in contact with any region of said one conductivity type; and forming source and drain regions in said region of opposite conductivity type adjacent said gate.
Claim 2
Independent Claim
239 words
A method of producing a Schottky-barrier, field-effect transistor comprising: providing a semiconductor body of one conductivity type and a low impurity concentration; forming an ion implantation layer of said one conductivity type through the surface of said body, said ion implantation layer having a higher impurity concentration than said semiconductor body; oxidizing said surface of the body to provide an electrically insulating oxide layer portion of said body over the ion implantation layer; masking an area of said insulating oxide layer wherein said area is surrounded by an exposed portion thereof; oxidizing the body again at a high temperature to increase the thickness of the exposed portion of said insulating oxide layer to form a field oxide layer; removing the mask and said thin oxide thereunder to expose a region of higher impurity beneath the area previously covered by the mask; forming a region of opposite conductivity type opposite to said one conductivity type in said body in the exposed region and extending the region of opposite conductivity type under a portion of oxide layer and into the semiconductor body beneath the ion implantation layer; providing a conductive gate forming a Schottky junction with an exposed portion of the region of opposite conductivity type and extending over the field oxide layer but not in contact with any region of said one conductivity type; and forming source and drain regions in said region of opposite conductivity type adjacent said gate.
Claim 3
Dependent Claim
38 words
The method of claim 1 wherein said electrically insulating field oxide layer is used as a mask in forming the region of opposite conductivity type and wherein the region of opposite conductivity type is formed by ion implantation.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the region of opposite conductivity type is formed by ion implantation.
Claim 5
Dependent Claim
19 words
The method of claim 3 wherein the electrically insulating material is an oxide material grown into the semiconductor body.
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) | 1984-07-13 | 1985-01-12 | 1985-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-13 | 1989-01-12 | 1989-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-13 | 1993-01-12 | 1993-07-14 | $7700.00 | Window Closed / Lapsed |