Method for fabricating a field effect transistor
US4210993A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 2, 1979 |
| Grant date | Jul 8, 1980 |
| Priority date | — |
| Expiry date | Feb 2, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/141
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A field effect transistor is fabricated by forming a silicon dioxide film having a region where said silicon dioxide film becomes thinner at that area on one surface of a silicon semiconductor substrate of a first conductivity type at which the field effect transistor is to be formed. On said silicon dioxide film there is deposited a polycrystalline silicon layer which has an impurity concentration higher than that of the silicon semiconductor substrate. The polycrystalline silicon layer is removed by selective etching so as to leave only a part which becomes a gate of the field effect transistor. A surface part of the silicon dioxide film over the entire area is removed by employing as a mask the part of the polycrystalline silicon layer to become the gate and to the extent that the surface of the silicon semiconductor substrate is exposed at the other part in the region, a silicon dioxide film is grown by thermally oxidizing the whole surface of the polycrystalline silicon layer to become the gate and the exposed surface of the semiconductor substrate, the silicon dioxide film produced at the surface of the polycrystalline silicon layer being thicker than the silicon dioxide film…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.