Deposition Temperature Effect on the Structure and Optical Property of RF‐PACVD‐Derived Hydrogenated SiCNO Film

Abstract

AbstractAmorphous hydrogenated silicon oxocarbonitride (SiCNO:H) films have been deposited by plasma‐assisted chemical vapour deposition (PACVD) using bis(trimethylsilyl)carbodiimide (BTSC) as a single source precursor in a argon (Ar) radio‐frequency plasma. In this work the SiCNO:H films deposited at different deposition temperatures were studied in terms of deposition rate, refractive index, surface roughness, microstructure, and chemical composition including bonding state. The results showed that a higher deposition temperature enhanced the formation of Si‐N bonds, and disfavoured the formation of N=C=N, Si‐NCN, C‐H and Si‐CH3 bonds. A higher deposition temperature also decreased the deposition rate and increased the refractive index of the resulting SiCNO:H film. With increasing temperature a denser film was formed, indicating a change of the deposition mechanism, i.e., transformation from particle precipitation to heterogeneous surface reaction. Except for the coatings deposited at room temperature, the surface of the films was smooth with a roughness of around 4 nm at the centre in the range of 5 μm x 5 μm area. Moreover, the films contained 8 ∼ 16 at.% oxygen bonded to Si, which originated from the remnant H2O in the deposition chamber.