Epitaxial silicon wafer
US10020203B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2017 |
| Grant date | Jul 10, 2018 |
| Priority date | — |
| Expiry date | Jan 6, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/83
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An epitaxial silicon wafer includes a silicon wafer consisting of a COP region in which a nitrogen concentration is 1×1012−1×1013 atoms/cm3, and an epitaxial silicon film formed on the silicon wafer. When heat treatment for evaluation is applied, a density of BMD formed inside the silicon wafer is 1×108−3×109 atoms/cm3 over the entire radial direction of the silicon wafer. An average density of the BMD formed in an outer peripheral region of the silicon wafer which is a 1-10 mm range separated inward from an outermost periphery thereof is lower than the average density of the BMD formed in a center region. A variation in the BMD density in the outer peripheral region is 3 or less, and a residual oxygen concentration in the outer peripheral region is 8×1017 atoms/cm3 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.