"Control of residual stress in thin films by substrate vibration and their mechanical property"

"The prevention of residual stress of thin film syntheses is very important in processing engineering surfaces. In this paper, details of residual stress control by thevibration of the substrate using PZT at voltage of 0-100 V are presented. The thin films deposited are crystalline TiN, Ti, Cu, Al films and amorphous C, Si films. The residual stresses are measured using Stoney's method. The results of our experiment show that for Ti, TiN and Cu thin films, compressive stresses are changed to tensile stresses. XRD and Auger spectroscopy results verify that the composition and crystalline structure of the treated and untreated crystalline thin films to be the same. But it is shown that the grain size in the film tend to decrease with increasing vibration amplitude. From the change of the microstructure of the film, a model for the control of residual stress is proposed. The change of adhesion strength is measured by a pin-on-disk tribo-tester with variation of the residual stress. The adhesion strength shows the maximum value at near zero residual stress. Therefore, control of residual stress by substrate vibration is shown to be an effective method for improving the wear life.