The thin‐film properties and temperature stability of titanium–tungsten nitride (TiWNx) Schottky contacts to GaAs have been investigated as a function of x, the atomic percent of nitrogen in the film. A Ti30W70 composite target was reactively sputtered onto GaAs substrates in nitrogen using argon as the diluent gas. The partial pressure of nitrogen was varied from 0% to 100%. This resulted in x varying from 0 to 27 at. %; however, the films contained a constant Ti–W atomic ratio of 0.18, regardless of x. The film stress and resistivity were well‐behaved and reproducible functions of x. Schottky contact characteristics were measured after annealing at several temperatures. After an 810 °C furnace anneal, the ideality factor (n) and barrier height (φB) displayed well‐defined, broad extrema as a function of x. Both the best average values of n and φB and their smallest standard deviations occurred for x=10 at. % of nitrogen. Thus the most stable and uniform TiWNx–GaAs Schottky contact was obtained from TiWN1...