Annealing kinetics of sputtered gold-tungsten and gold-molybdenum films

The annealing kinetics of sputtered Au–W and Au–Mo films have been investigated as a function of temperature up to 500°C. The electrical resistivity of the gold layer after deposition was measured to be 1.25 times the bulk resistivity. The excess resistivity was attributed to structural defects such as vacancies, interstitials, twins, dislocations, and impurities which were quenched in during deposition. Particle size changes in Au–W and Au–Mo occur in two stages, with an activation energy for gold of 0.4 eV below 200°C and 0.7 eV above 200°C. The activation energy for the refractory layer particle growth was 1.8 eV up to 500°C. The kinetics of dislocation (Nd) annealing at 500°C was determined to follow an equation of the form Q(Nd) = − A(Nd)m, with m = 3. Annealing the films up to 500°C resulted in a decrease of internal stress in gold from 2.5 × 109 dyn/cm2. The observed results are discussed in terms of microstructural changes and the dependence of internal stress on film thickness.