Temperature bistability in a silicon wafer with a doped layer on lamp-based heating

The effect of a heavily doped layer formed at the surface of a lightly doped silicon wafer upon the transfer characteristic of the entire heat system involving the wafer, lamp heater, and cooling system is simulated. The layer parameters that provide the hysteresis-loop-shaped transfer characteristic are determined. The dependence of the integrated emissivity of the silicon wafer with a doped layer on the layer thickness, doping level, and position with respect to the radiation source is analyzed. It is shown that, in the temperature region of semitransparency of the silicon wafer, there exists some critical layer thickness such that the integrated emissivities of both sides of the wafer are equal. It is found that the parameters of the hysteresis loop depend on the layer position with respect to the radiation source. The expression for the layer-related correction to the temperature of the wafer when subjected to thermal processing in a lamp reactor with supplementary heat removal by convection or heat conduction is derived.