Refractory metal silicides, such as tungsten silicide (WSi x ), have been used for integrated circuit interconnect and self-aligned MESFET gates because of their low resistivity and thermal and chemical stability. These same characteristics make refractory metal silicides interesting materials for prospective use in micromechanical structures. However, little information on residual stresses, elastic moduli, or other micromechanical properties has been available for refractory metal silicide films.
This paper presents morphology and stress characteristics of sputter-deposited tungsten silicide films, including orientation-dependent variations, as functions of deposition parameters. The biaxial elastic modulus and thermal coefficient of expansion are found for our sputtered films. Stress-measurement methods and annealing are discussed. Released diaphragms of different sizes and shapes, having controlled residual stress, have been fabricated.