A New Non-Contact Method to Measure Temperature of the Surface of Semiconductor Wafers

Abstract

A new direct and non-contact method to determine temperature of the surface of semiconductors by measurements of the refractive index using reflection ellipsometry is proposed. Use of a probing light larger than band gap in energy enhances the change of the refractive index, so that the temperature dependence of the index can be expressed by a simpie formula. Experimental results are in good agreement with the calculations. A temperature resolution of 0.3°C is expected with an ellipsometer resolving to the fourth decimal.