MEASUREMENTS OF THE INTRINSIC STRESS IN THIN METAL-FILMS

In this paper the results of experiments are discussed, in which the stress of thin metal films was measured in situ under uhv conditions with a bending beam apparatus. While only tensile stresses are built up in high melting point metals, comparatively small tensile as well as compressive stresses are sequentially built up in low melting point metals. It is demonstrated that the different types of stress curves can be correlated with different growth modes (e.g. columnar grain growth or island growth) caused by differences in the material mobility. A model for the origin of the internal stress is used to interpret the stress curves in terms of the microstructure of the films. It is shown that stress measurements can be used to study the influence of deposition parameters (e.g. gas ambient, substrate temperature etc.) on the growth and structure of thin films. Finally it is demonstrated that stress measurements can even be used to study gas adsorption on vapor-deposited films. © 1990.