On the evolution of residual stress at different substrate temperatures in sputter-deposited polycrystalline Mo thin films by x-ray diffraction

The evolution of in-plane biaxial residual stress in polycrystalline Mo thin films deposited on Si at different substrate temperature were investigated using x-ray diffraction methods. The analyses were performed using both single and multi hkl reflection peak shifts methods in the asymmetric grazing incidence geometry. High compressive stress builds up in films synthesized at low substrate temperature while tensile stresses which are relatively low in magnitude manifest themselves at high substrate temperature. While such an evolutionary pattern is a direct consequence of competition between the intrinsic and thermal components of stress and varies as a function of temperature, the predominant cause of intrinsic compressive stress in Mo films deposited at low substrate temperature was traced to oxygen impurities incorporated in the film during the growth process.