Effects of the Nitrogen Flow Ratio and Substrate Bias on the Mechanical Properties of W-N and W-Si-N Films

Abstract

The reactive gas flow ratio and substrate bias voltage are crucial sputtering parameters for fabricating transition metal nitride films. In this study, W-N films were prepared using sputtering with nitrogen flow ratios (f) of 0.1-0.5. W-N and W-Si-N films were then prepared using an f level of 0.4 and substrate bias varying from 0 to -150 V by using sputtering and co-sputtering, respectively. The variations in phase structures, bonding characteristics, mechanical properties, and wear resistance of the W-N and W-Si-N films were investigated. The W-N films prepared with nitrogen flow ratios of 0.1-0.2, 0.3, and 0.4-0.5 displayed crystalline W, amorphous W-N, and crystalline W2N, respectively. The W-N films prepared using a nitrogen flow ratio of 0.4 and substrate bias voltages of -50 and -100 V exhibited favorable mechanical properties and high wear resistance. The mechanical properties of the amorphous W-Si-N films were not related to the magnitude of the substrate bias.