Effect of heat treatment after deposition on internal stress in molybdenum films on SiO2/Si substrates

Abstract

The stress in Mofilms evaporated by an electron‐beam gun onto SiO2/Si substrates has been studied as a function of temperature of heat treatment after deposition. The structure of the films was observed by x‐ray diffraction line breadth and scanning electron microscope. Both tensile stress σ H T and columnar grain size 〈D〉 increased linearly with temperature in the range of 600°–1000°C (σ H T =0.6/2.0×109 dyn/cm2, 〈D〉=120/1300 Å at 600°/1000°C) and σ H T nearly stopped increasing above 1000°C. Such σ H T and 〈D〉 behavior can be explained semiquantitatively by the Nakajima–Kinosita model wherein the internal stress can be built up by the volume contraction due to the increase in grain size. It was found that the electrical resistivity of the films was also dominated by the columnar grain boundary.