Experimental study of the effect of process parameters on plasma-enhanced chemical vapour deposition of silicon nitride film

The effect of plasma-enhanced chemical vapour deposition parameters on refractive index and deposition rate of silicon nitride films is investigated. Usually, this kind of study is performed in a laboratory system. In the present work, a horizontal batch system for the simultaneous coating of 100 silicon wafers is used. Using a gas mixture of silane and ammonia as the reactant-gas sources, the effects of the gas flow rate ratio (R = NH3/SiH4 with the total flow rate constant), pressure, power and temperature on the refractive index and deposition rate were studied and the experimental results are presented and discussed.

► Study of industrial PECVD parameters on refractive index and deposition rate of SiNx. ► The gas flow rate ratio R is a major process parameter. ► Pressure increase leads to refractive index increase and deposition rate decrease. ► Power is a sensible parameter for the deposition rate but not for the refractive index. ► Temperature change leads to refractive index change and moderate deposition rate change.