Process for producing undercut dummy gate mask profiles for MESFETs
US4732871A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1987 |
| Grant date | Mar 22, 1988 |
| Priority date | — |
| Expiry date | Mar 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/017
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Process for producing temperature-stable undercut profiles for use in semiconductor fabrication. The process is based on the phenomenon of high etch-rate selectivity between RF- and LF- PECVD-grown silicon nitride films (12G and 13G, respectively) that are deposited on top of each other. By choosing proper film and process parameters, these PECVD nitride structures can be made stress-free: the tensile stress of the RF film (12G) compensates the compressive stress of the LF film (13G). Also disclosed is an application of a T-shaped structure (15), produced with the new process, in a method for fabricating fully self-aligned "dummy" gate sub-micron MESFETs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.