Thin-Film Calibration Wafer Materials for RTP Temperature Measurement
Kenneth G. Kreider, John G. Gillen
We are developing an instrumented calibration wafer for radiometric temperature measurements that uses thin-film thermocouples to minimize the thermal disturbance of the wafer by the sensors. The thin-film thermocouples are sputter deposited on a thermally oxidized silicon wafer. The NIST calibration wafer also employs platinum-palladium wire thermocouples to achieve a standard uncertainty of 0.4 C in temperature measurement of the thin-film thermocouple junction at 900 C. The high temperatures of the wafer require the development of new thin-film material systems. We report the results of our testing of sputtered platinum, palladium, rhodium, iridium, rhenium, and tungsten thin-films using titanium bond coats on thermally oxidized silicon wafers. Depth profiling, with secondary ion mass spectrometry, was used to determine the diffusion profiles from the metal film to the silicon after heat treatments as high as 1000 C. Electron microscopy and optical microscopy were used to follow reactions and the deterioration of the thermoelectric films. In addition, performance tests up to 1000 C in the NIST RTP test bed were used to determine the stability of the material systems under industrial conditions. Failure mechanisms and limitations of the thin-film thermocouple materials are discussed with data on hysteresis and drift in thermometry performance. The result of our evaluations indicate that Rh/Ir thin-film thermocouples have the best properties for wafer temperatures abouve 900 C.
Proceedings of the 7th International Conference on Advanced Thermal Processing of Semiconductors
July 1, 1999
International Conference on Advanced Thermal Processing of Semiconductors
and Gillen, J.
Thin-Film Calibration Wafer Materials for RTP Temperature Measurement, Proceedings of the 7th International Conference on Advanced Thermal Processing of Semiconductors
(Accessed December 1, 2023)