Evaluation method of silicon wafer
US11060983B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2018 |
| Grant date | Jul 13, 2021 |
| Priority date | — |
| Expiry date | Jul 23, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8848
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An evaluation method of a silicon wafer allows non-destructive and non-contact inspection of a slip that affects the electrical properties of semiconductor devices, without being subjected to restrictions of the surface condition of silicon wafers or processing contents as much as possible. The evaluation method of a silicon wafer includes a step of section analysis where a surface of a single crystal silicon wafer after thermal processing is divided by equally-spaced lines into sections with an area of 1 mm2 or more and 25 mm2 or less and the existence of strain in each of the sections is determined based on a depolarization value of polarized infrared light, and a screening step where the wafer is evaluated as non-defective when the number of adjacent sections being determined to have strain by the section analysis step does not exceed a predetermined threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.