Ni-silicide precursor for gate electrodes

Abstract Ni-silicide film was deposited at a low temperature of 160 °C by CVD using a Ni(PF 3 ) 4 /Si 3 H 8 gas system. Injecting Si 3 H 8 during the Ni deposition does not affect the deposition rate, but the step-coverage quality deteriorates at high growth temperatures. At high growth temperatures, the Ni/Si ratio of the film deposited on the sidewall varies as the distance from the open area increases. High step-coverage quality and a constant Ni/Si ratio independent of the location of the deposition are strongly required to fabricate a three-dimensional device. These requirements were achieved with this CVD by depositing the Ni-silicide film below 180 °C.