Stress Modification in Tungsten Films Deposited by Ion-Assisted Evaporation

Abstract

ABSTRACTThe modification of film stress in evaporated tungsten was studied as a function of deposition environment. Using concurrent ion bombardment of the growing film, the stress was seen to vary systematically with ion energy, ion flux, and substrate temperature. The qualitative behavior fits the model of stress modification developed for niobium films. X-ray diffraction was used to study the structure of the films, and a clear correlation between crystallographic texture and film stress is found. The original structure/impurity model for film stress modification due to ion bombardment has been modified to account for the relationship between film stress and texture.