Method of making a field effect transistor
Abstract
Abstract A field effect transistor having a gate on the bottom of a groove in a body of semiconductor material with the source and drain being on a surface at opposite sides of the groove is made by first forming a recess in the surface of the semiconductor body. A metal layer is then coated on the surface of the semiconductor body and on the surfaces of the recess. A layer of a photoresist is then coated over the metal layer. The photoresist is then exposed to a beam of light whose rays extend along a path which is at a very small angle with respect to the surface of the semiconductor body to fully expose a narrow portion of the photoresist layer at one edge of the recess. The fully exposed portion of the photoresist layer is removed to expose a narrow area of the metal layer along the edge of the recess. The exposed portion of the metal layer is then removed and a groove is formed in the portion of the surface of the semiconductor material exposed by removing a portion of the material layer. A metal film is coated on the bottom of the groove to form the gate of the field effect transistor with the metal layer on the bottom of the recess at one side of the groove and the metal layer on the surface of the semiconductor body at the other side of the groove forming the source and drain of the field effect transistor.
Inventors
- 👤 Jitendra Goel
Bibliographic Details
Claims Analysis
Total Claims: 8References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-25 | 1983-09-24 | 1984-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-25 | 1987-09-24 | 1988-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-25 | 1991-09-24 | 1992-03-25 | $7700.00 | Window Closed / Lapsed |