Radio frequency source power-induced ion energy impact on SiN films deposited using a room temperature SiH4-N2 plasma

Using a SiH4-N2 plasma, silicon nitride films were deposited at room temperature. The impact of source power ranging from 500 to 900 W and ion energy are investigated. The film properties examined include a deposition rate, a refractive index, and a surface roughness. Ion energy diagnostics was conducted to explore the relationships between ion energy and film properties. A variation in ion energy with source power was quite complex. By contrast, a decrease in ion energy flux was observed for a decrease in the source power. An increase in the deposition rate with the decrease in source power was attributed to enhanced ion energy. The refractive index strongly correlated with low ion energy flux. A decrease in surface roughness in the range of 500-700 W was related to larger ion energy. The deposition rate, refractive index, and surface roughness were varied in the range of 0.27-0.35 nm/sec, 1.690-1.739, and 6.7-52.5 nm, respectively.