Induced bistable behavior in elements of the thermal reactor at silicon wafer heating in bistability mode

Abstract

The work studies the induced bistability phenomenon in a thermal reactor elements involved in radiation heat exchange with the silicon wafer exhibiting bistable behavior. The heat balance equations for a silicon wafer and elements of a thermal reactor: a heater, a quartz window, and an absorber are derived. The control parameters in such a system were the heater temperature and the effective heat transfer coefficients, which characterize the heat removal from the quartz window and the radiation absorber by external agents. The effective heat transfer coefficient, which is responsible for the conductive component of the heat flux from the silicon wafer to the absorber, was also used. Simplified models of the thermal reactor are considered: first, with the quartz window and the absorber with its constant temperature, and second, without the quartz window and with the absorber varying its temperature. It is shown that in the quartz window and absorber there is the effect of induced bistability within the scope of both models. The evolution of a shape of a hysteresis loop is explained at the varying values of the heat exchange coefficients. It is found that temperature jumps of absorber in the instability points of bistable curve for the tungsten heater increases of two orders of value in compared with the heater whose optical properties are that of a blackbody. The explanation of the effect is suggested.