Low-temperature-deposited insulating films of silicon nitride by reactive sputtering and plasma-enhanced CVD: Comparison of characteristics

摘要

The characteristics of SiNx films deposited by reactive sputtering and plasma-enhanced chemical vapor deposition (PECVD) are examined to obtain high-density films at low deposition temperatures. PECVD SiNx films deposited at 200 degrees C show low densities of 2.14-2.20g/cm(3) regardless of their composition, while their refractive index varies depending on their composition. PECVD requires the substrate temperature to obtain high-density films, because a possible cause of low-density films is the amount of Si-H bond, rather than that of N-H bond, in the films originating from hydrogen incorporated by the insufficient decomposition of SiH4 molecules at low temperatures. The sputtered SiNx films with high density are obtained at a temperature lower than 200 degrees C and considered a promising candidate for insulating films at low process temperatures. (C) 2016 The Japan Society of Applied Physics