Photoacoustic measurements of silicon wafer processing temperatures

Temperature measurements of silicon wafers in semiconductor processing conditions using acoustic techniques are being investigated. Theoretical models for the temperature dependence of zeroth-order Lamb waves have been developed. Initial experimental data for zeroth-order antisymmetric Lamb waves and acoustic waves through a layer of ambient above the silicon wafer have been obtained. The temperature measurement of the layer of ambient is expected to have sensitivities better than ±1°C, and it is expected that this measurement will yield the temperature of the bulk of the wafer as well