Use of polymer spacers for the fabrication of shallow trench isolation regions with rounded top corners
US5801083A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1997 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Oct 20, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming insulator filled, shallow trench isolation regions, with rounded corners, has been developed. The process features the use of a polymer coated opening, in an insulator layer, used as a mask to define the shallow trench region in silicon. After completion of the shallow trench formation the polymer spacers are removed, exposing a region of unetched semiconductor, that had been protected by the polymer spacers, during the shallow trench dry etching procedure. The sharp corner, at the intersection between the shallow trench and the unetched region of semiconductor, is then converted to a rounded corner, via thermal oxidation of exposed silicon surfaces. The polymer spacers also eliminate the top corner wraparound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.