Modeling and control of the wafer temperatures in a diffusion furnace

Abstract

In this paper the thermal behavior of a diffusion furnace is studied. The ultimate goal is to achieve control of the wafer temperatures. It is shown how some previous results from the literature on the behavior of wafer temperatures in a diffusion furnace are incomplete and partly erroneous. A control algorithm has been derived which achieves much better wafer-to-wafer uniformity than conventional control.