HEAT-TRANSPORT IN COLD-WALL SINGLE-WAFER LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION REACTORS

A model is formulated to understand and predict wafer temperatures in a tungsten low pressure chemical-vapor-deposition (LPCVD) single-wafer cold-wall reactor equipped with hot plate heating. The temperature control is usually carried out on the hot plate temperature. Large differences can occur between the susceptor and the wafer temperature, especially at the typically low pressures for LPCVD systems. Verification of the model was done by measurements of the true wafer temperatures as a function of total pressure, gas composition, gas flow, and coatings of wafer and susceptor. A good agreement between model and measurements was found by considering the heat transport by radiation and gas conduction.