Kinetics and Mechanism of Selective Tungsten Deposition by LPCVD

Tungsten films have been deposited selectively on oxide‐patterned silicon wafers by the reduction of in and gas flow systems. The deposition rate of films was investigated as a function of reactant partial pressures. The reaction orders with respect to and are zero and one‐half, respectively. Under given experimental conditions, the growth rate of the selectively deposited W films was reduced by 32% when the deposition area increased by a factor of 10–100. This decrease in growth rate can be attributed to the effect of on the surface reaction. The selective nature of the process deteriorates with increasing deposition rate, partial pressure, partial pressure, or deposition time. The loss of selectivity seems to be linked to an increase in partial pressure in the reactor.