IrSi3/p‐Si Schottky diodes have been fabricated by a molecular beam epitaxy technique at 630 °C. Good surface morphology was observed for IrSi3layers grown at temperatures below 680 °C, and an increasing tendency to form islands is observed in samples grown at higher temperatures. Good diode current‐voltage characteristics were observed and Schottky barrier heights of 0.14–0.18 eV were determined by activation energy analysis and spectral response measurement.