Materials and methods for etching silicides, polycrystalline silicon and polycides
US5219485A · kind A · utility
24Cited by
5References
9Claims
0Family size
Assignee
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Key dates
| Filing date | Oct 17, 1991 |
| Grant date | Jun 15, 1993 |
| Priority date | — |
| Expiry date | Oct 17, 2011 |
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.