Formation of WxSi1−x by plasma chemical vapor deposition

Smooth films of W-Si compounds (WxSi1−x) were successfully formed by plasma chemical vapor deposition using WF6 and SiH4. The atomic ratio of W/Si in the film depended on the flow rate of WF6/SiH4. The WxSi1−x obtained when x was less than 0.45 was amorphous even after the film was annealed at 1100 °C for 60 min in N2 ambient. The crystalline phase of W was observed when x is 0.99 in an as-deposited film. Distribution of W atoms in the film was found to be uniform. Resistivities of as-deposited films varied from ∼3×10−2 to ∼4×10−5 Ω cm, corresponding to x of from 0.04 to 0.99. For smaller x, the decrease in resistivity on annealing was marked.