Materials and methods for etching silicides, polycrystalline silicon and polycides
US5112435A · kind A · utility
15Cited by
6References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1989 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Nov 29, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Gas chemistry and a related RIE mode process is described for etching silicides of the refractory metals titanium, tantalum, tungsten and aluminum and for etching composites of these silicides on polycrystalline silicon layers. BCl.sub.3 is added to the HCl/Cl.sub.2 gas chemistry used for the polysilicon etch along with additives selected from fluorinated gases and oxygen to satisfy the multiple requirement of the two-step silicide-polysilicon etch process, including the silicide-to-polysilicon etch ratio requirement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.