Mos semiconductor structure with increased field threshold and method for making the same
Abstract
Abstract An MOS semiconductor structure and method for making the same in which a semiconductor wafer is treated to form an thin oxide layer having a net charge. In a specific embodiment a positive net charge is introduced into the oxide layer through introduction of chrome ions. Field oxide is then grown over the thin oxide layer. The field oxide and thin oxide layers are removed from selective portions of the semiconductor wafer. Source and drain diffusions are made into the semiconductor wafer and a gate oxide along with gate source and drain electrodes are formed. The introduction of the positive oxide charge over the field region increases the field voltage threshold and permits use of a thinner field oxide.
Inventors
- 👤 W Brand
- 👤 F Kashkooli
Bibliographic Details
Claims Analysis
Total Claims: 3References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |