Effect of Bias Voltage and Discharge Current on Mechanical Properties of TiN Film Deposited by D.C. Magnetron Sputtering
Hirotaka TANABE, Yoshio MIYOSHI, Tohru TAKAMATSU and Hideyuki SUGIURA
Abstract:A study on the effects of bias voltage and discharge current on the mechanical properties of TiN films deposited on carbon steel S45C by reactive D.C. magnetron sputtering was carried out. The residual stress, hardness, toughness and adhesive strength was examined by X-ray method, nano-indentation hardness test, IF method and scratch test, respectively. Quite large compressive residual stress was evaluated and it increased as the bias voltage or discharge current increased. With increasing bias voltage or discharge current, the hardness increased, but the adhesive strength decreased. The toughness increased with increasing bias voltage. The each change of these properties had a good correlation with the change of the residual stress, and was arranged as a data-band regardless of the difference of coating conditions. It was considered that these properties were mainly depended on the residual stress. The half value breadth of X-ray diffraction peak also increased with increasing bias voltage or discharge current, and the change of residual stress showed a good correlation with the change of the half width breadth. It was confirmed the residual stress was produced by the bombardments of high-energy ions toward TiN film in coating process. It was concluded that the increase of bias voltage and the increase of discharge current had a same effect to promote the ion bombardment, and the ion bombardment dominantly influenced the mechanical properties of TiN films. Key Words:TiN film, Sputtering, Residual stress, Hardness, Toughness, Adhesive strength, X-ray diffraction