Remote True Temperature Pyrometry of Si Wafers: Theoretical and Practical Considerations

Abstract

ABSTRACTThe problems of real thermodynamic temperature measurement in semiconductor processing can be divided into fundamental and environmental. The first type arises from a-priori unknown and in process changing optical properties (emissivity) of the target wafer. Others have to do with the need to eliminate direct and indirect stray heat flux from entering into the sensor. We describe the advantages and pitfalls of various (passive and active) remote measurement methods. Experimental results of a novel emissivity independent technique for real time measurement in the range of 450–850°C with accuracy better than 1% for wafer emissivity in the range of 0.2 to 0.95 are given.