finFET isolation by selective cyclic etch
US9209178B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2013 |
| Grant date | Dec 8, 2015 |
| Priority date | — |
| Expiry date | Nov 25, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P80/30
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Etching interleaved structures of semiconductor material forming fins of finFETs and local isolation material interposed between the fins is performed alternately and cyclically by alternating etchants cyclically such as by alternating gases during reactive ion etching. Etchants are preferably alternated when one of the semiconductor material and the local isolation material protrudes above the other by a predetermined distance. Since protruding surfaces are etched more rapidly than recessed surfaces, the overall etching process is accelerated and completed in less time such that erosion of other materials to which the etchants are less than optimally selective is reduced and allow improved etching of trenches for improved isolation structures to be formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.