Probing periodic oscillations in a silane dusty plasma in a very high-frequency plasma enhanced chemical vapor deposition process

To estimate the dust formation time scale in a silane–hydrogen plasma, optical and electrical plasma diagnostics are performed. We report a periodic fluctuation in emission intensity and electric current in a dusty plasma. The trends of the frequency of fluctuations with varying substrate temperatures and gas flows are studied. However, no such fluctuation is observed in the nondusty plasma. It is hypothesized that this fluctuation arises from the periodic formation and ejection of a dust cloud via the void formation when a critical dust size is reached.