Technique for precision temperature measurements of a semiconductor layer or wafer, based on its optical properties at selected wavelengths
US5258602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1991 |
| Grant date | Nov 2, 1993 |
| Priority date | — |
| Expiry date | Mar 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for sensitive and precise determination of the temperature of a thin layer or wafer of bandgap material, without requiring contact to the layer or to the wafer, is based on selection of optical wavelength or wavelengths and the measurements of transmittance through the sample at such wavelength(s). The relationship between the temperature variations of the absorption coefficient, whether determined by band-to-band absorption or a totally different mechanism, and the measured transmittance, provide an indication of the sample temperature, without regard to the ambient temperature. The method prescribes how to select the wavelength(s) based both on the intrinsic properties of the material and on the practical considerations of the measurement situation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.