Study on the Preparation Technology of SiNx Thin Film by PECVD

To prepare SiNx thin film with good compactness, fast deposition rate and stable performance, plasma-enhanced chemical vapour deposition (PECVD) is adopted to study the influences of different technological parameters on the properties of SiNx thin film. The experimental results indicate that SiH4 and NH3 flow rate, temperature, radio-frequency power, pressure and other technological parameters all have influences on the properties of SiNx thin film. Among them, the flow ratio of SiH4/NH3 has crucial influences on the refractivity of SiNx; and SiH4 flow rate and radio-frequency power have important influences on the deposition rate of SiNx. According to the discussion results, the optimal technological conditions to prepare SiNx thin film are obtained, with the refractivity of SiNx of 2.2 and deposition rate of 34.79 nm/min. It is proved that PECVD can be utilized to prepare high-quality SiNx thin film with controllable refractivity and deposition rate.