Method of removing impurity metals from semiconductor devices
US4231809A · kind A · utility
91Cited by
9References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 25, 1979 |
| Grant date | Nov 4, 1980 |
| Priority date | — |
| Expiry date | May 25, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/024
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process is disclosed for gettering deleterious metal impurities, particularly the transition metals such as Cu, Fe, Co, Ni and Cr from silicon wafers by high temperature treatment for a comparatively short time in a hydrogen chloride vapor at low oxygen pressure. The low oxygen pressure inhibits the oxide growth on the silicon surfaces to thicknesses of not more than about 150 Angstroms, sufficient to protect the silicon surface but not so thick as to constitute a barrier to outdiffusion of the gettered impurities. This particular process may be preceded and followed by other previously known gettering techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.