Method for forming a shallow trench with tapered profile and round corners for the application of shallow trench isolation (STI)
US5807789A · kind A · utility
44Cited by
4References
28Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1997 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Mar 20, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/978
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention is a method for forming a shallow trench with tapered profile and round corners for the application of shallow trench isolation (STI). This invention utilizes a multiple-step dry etching process with reduced RF power and increased pressure to etch a shallow trench. This takes advantage of different degree of polymer deposition in different steps by varing the pressure and the RF power. Thus, a shallow trench with tapered profile and round corners is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.