Combined emissivity and radiance measurement for determination of temperature of radiant object
US5993059A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1998 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Mar 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J5/0813
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method of measurement of emissivity and radiance of a wafer in a rapid thermal processing chamber enables determination of wafer temperature and control of temperature of the wafer. Mirrors enclose the chamber and reflect radiation from lamps within the chamber to heat the workpiece of interest. One or more viewing ports are provided in one of the mirrors to allow for the egress of radiant energy emitted by the wafer. The wavelength of the exiting radiation is selected by an optical filter having a passband which passes radiation at wavelengths emitted by the wafer while excluding radiation emitted by heating lamps. A chopper having surface regions differing in their reflectivity and transmissivity is positioned along an optical path of radiation propagating through the one or more ports, this resulting in a pulsation of detected radiation. The ratio of the detected intensities of the radiation pulses is used to determine wafer reflectance based on reflectivity and transmissivity of the reflective portion of the chopper. The maximum intensity of radiation is also taken as a measure of radiance. The reflectance is employed to calculate the emissivity, and the emissivity…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.