Hybrid high power impulse and radio frequency magnetron sputtering system for TiCrSiN thin film depositions: Plasma characteristics and film properties

TiCrSiN thin films were successfully grown using a hybrid approach in which a high power impulse magnetron sputtering (HiPIMS) power was combined with a radio frequency (RF) power. Different Si contents were obtained by changing the RF power of Si target. The ion energy distribution functions (IEDFs) showed that the energy tails of all sputtered ions from the targets and sputtering gases shifted to a higher energy tails when the Si target power increased from 50 to 150 W. The peak power density of the TiCr target powered by HiPIMS and the corresponding Si content in the films increased from 1214 to 1350 W/cm² and from 0.2 to 17.9 at.%, respectively, as the Si target power increased from 50 to 150 W. The Si atoms were in the form of amorphous Si₃N₄ phase. The Si content showed a major influence on the microstructure, adhesion and mechanical properties of TiCrSiN film. Although a nanocomposite microstructure was formed when the Si content was 17.9 at.%, lower hardness and acceptable adhesion property were obtained due to a microstructure consisting of small TiN nanograins embedded in a large amount of soft amorphous silicon nitride matrix. The hardness of TiCrSiN film reached a maximum hardness of 31.1 GPa at Si = 6.7 at.% due to the refined microstructure and grain boundary hardening effect.