Formation of crystalline and amorphous phases during deposition of Ni xTi1-x, thin films on silicon substrates interpretation of experimental results using molecular dynamics simulations

Abstract

This research was undertaken to study the crystallization and amorphization of magnetron-sputtered NixTi1-x thin films using composition variation and various substrate bias voltages. Variation of deposition efficiency with composition and bias voltage suggests that Ni resists resputtering. In the case of Ti thin films, the increase in negative bias voltage caused decrease in crystallinity due to re-sputtering. But, the bias voltage did not affect the crystallinity of Ni thin film significantly. On the other hand, high bias voltage induced crystallinity in otherwise amorphous NixTi1-x thin films. In order to explain some of the observed trends, molecular dynamics simulations based on embedded atomic method (EAM) potential for Ni-Ti system were carried out. Simulations could explain the partial amorphization of crystalline films and partial crystallization of amorphous films which occurred due to re-sputtering.