Optimization of dry etching through the control of helium backside pressure
US5624582A · kind A · utility
257Cited by
8References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1994 |
| Grant date | Apr 29, 1997 |
| Priority date | — |
| Expiry date | Mar 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In a dry non-isotropic etching process, backside cooling by helium controls the rate and uniformity of etching in a thermal silicon layer, the taper of profiles etched into silicon dioxide layers, and the dimension and uniformity of etched structures in a polycide or polysilicon layer, on the surface of a silicon wafer. Helium pressures from greater than 2 torr to more than 10 torr are satisfactorily utilized to produce these effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.