Parametric study and residual gas analysis of large-area silicon-nitride thin-film deposition by plasma-enhanced chemical vapor deposition

Large-area silicon-nitride thin films deposited from silane and ammonia by plasma-enhanced chemical vapor deposition are investigated experimentally in a 300 mm apparatus with a vertical showerhead. The responses of deposition rate and refractive index to the process parameters are found and discussed. The effects of shower-head configuration on the full-wafer deposition rate and refractive index are further examined, and the inherent non-uniformity is improved by using a proper convex showerhead. The residual gases are analyzed online, and a good correlation between the partial pressure of hydrogen and the deposition rate is found.