Comparison of silicon wafer temperature measurements using thin film thermocouples and lightpipe radiation thermometers in a thermometry test bed

This paper reports on the results of a research study to compare the temperature measurements obtained using NIST (National Institute of Standards and Technology) thin-film. thermocouple calibration wafers and other commercial calibration wafers to those of lightpipe radiation thermometers (LPRTs) from at least two commercial manufacturers. These comparisons have been performed in the UT (The University of Texas at Austin) RTP Thermometry Test Bed, which has been previously described. The LPRT-to-thermocouple comparison measurements have been made at temperatures ranging from 700°C to 900°C in the UT Test Bed. The Thermometry Test Bed is a joint project by UT, NIST, SA (SensArray Corporation) and ISMT (International SEMATECH) under Sponsored Research Agreement No. 38060302. The Test Bed facility is evolving into a temperature standard, traceable to ITS-90, for commercial sensors (OEM pyrometers) targeting applications in RTP and (MO)CVD. The Test Bed facility can accommodate a wide variety of commercial sensors. The performance of the Test Bed is indicated by the following wafer temperature characteristics: run-to-run repeatability better than ±1.0°C at 1000°C, and overall temperature uniformity better than ±1.5°C across the wafer (better than ±1.0°C at any given radial location). Results using standard TC (thermocouple) instrumented wafers from SA are presented to characterize the performance of the Test Bed, as well as results from the NIST thin-film thermocouple calibration wafers. Several commercial sensor suppliers have initiated tests of their pyrometers. The pyrometers tested in this study are the CI Systems NTM500, and the Mikron Instrument Company´s M680S IR Fiberoptic Temperature Measuring System.