Anisotropic etch method
US5167762A · kind A · utility
20Cited by
7References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 2, 1991 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | Jan 2, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method to anisotropically etch an oxide/poly/oxide or an oxide/poly/oxide sandwich structure on a silicon wafer substrate in situ, that is, using a single parallel plate plasma reactor chamber and a single inert cathode, with a variable gap between cathode and anode. This method has an oxide etch step and a silicide/poly etch step. In the poly removal step, helium is added to improve etch uniformity. The pressure, power, and various gas quantities are balanced to produce the fastest etch rates while preserving selectivity. The fully etched sandwich structure has a vertical profile at or near 90.degree. from horizontal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.