The structure and thermal stability of bimetallic Au‐Ta films has been studied by x‐ray diffraction, electrical resistivity, and by microscopy. Annealing above 450 °C forms a TaAu compound. The growth of the TaAu layer at the Au&sngbnd;Ta interface follows a parabolic rate law. A low‐temperature depletion of gold at tantalum grain boundaries occurs below 350 °C with an activation energy of 0.41 eV. Grain growth occurs with an activation energy of 0.50–0.55 eV for gold and 0.40–0.50 eV for tantalum. Thermal stresses of the order of 1.0×109dyn/cm2exist in the sputtered films.