Method for heat treatment of silicon substrate, substrate treated by the method, and epitaxial wafer utilizing the substrate
US6143071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1999 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Jun 30, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B33/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
There is disclosed a method for heat treatment of a silicon substrate produced by the CZ method by utilizing a rapid thermal annealer, wherein the heat treatment is performed under an atmosphere composed of 100% nitrogen, or 100% oxygen, or a mixed atmosphere of oxygen and nitrogen by heating the silicon substrate to a maximum holding temperature within a range of from 1125.degree. C. to the melting point of silicon, and holding the substrate at that maximum holding temperature for a holding time of 5 seconds or more, and then the substrate is rapidly cooled at a cooling rate of 8.degree. C./second or more from the maximum holding temperature. In the method, the amount of oxygen precipitation nuclei in the substrate can be controlled by changing the maximum holding temperature and the holding time. The present invention provide a method for heat treatment of a silicon substrate produced by the CZ method by utilizing an RTA apparatus, which can provide a silicon substrate having a desired oxygen precipitation characteristic without controlling oxygen concentration in the silicon substrate, and an epitaxial wafer utilizing a substrate heat-treated by the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.