Effect of substrate temperature on crystal orientation and residual stress in radio frequency sputtered gallium-nitride films

The effect of substrate temperature on the crystal orientation and residual stresses of gallium-nitride (GaN) films obtained by sputtering was discussed. X-ray diffraction method was used for the study. The GaN films were deposited at various substrate temperatures and the gas pressure and input power were kept constant. The crystal sizes of the films deposited at high temperatures were found to be larger than those obtained at low substrate temperatures. All films except that deposited at 973K exhibited a compressive residual stress which was observed to be decreasing with increase in temperatures.