An equipment model for polysilicon LPCVD

An equipment model has been developed for the low pressure chemical vapor deposition (LPCVD) of polycrystalline silicon in a horizontal tube furnace using a methodology which combines physical modeling with statistical experimental design. The model predicts the wafer to wafer deposition rate down the length of the tube and is intended to aid the process engineer in the operation of equipment, including the selection of optimum process parameters and process control based on measured deposition thicknesses. Kinetic and injection parameters in the model were calibrated using a series of nine statistically designed experiments which varied four parameters over three levels. The model accurately predicts the axial deposition profile over the full range of experimentation, and demonstrates good extrapolation beyond the range of experimental calibration