Granular metal‐semiconductor barriers were investigated onn‐type Si, GaAs, and CdSe single crystals. The barriers were formed by cosputtering metals, Au or Ni, and insulators, SiO2or Al2O3, onto the semiconductor surface. By varying the relative volume fraction of the insulator over the range 0–90%, the structure of the granular metal changed from that of a continuous metal to that of isolated small([inverted lazy s]20  Å )metallic particles embedded in the insulator. Even with as little as 10% by volume of the metal, the granular metal contacts were found to behave as metal‐semiconductor Schottky barriers. In the composition range 60–90% insulator in the granular metal, the barrier heights were independent of composition and their values were 0.57, 0.58, and 0.65 eV on Si, GaAs, and CdSe, respectively. In the case of Si and GaAs, the barriers are significantly lower than those observed for the pure metals; in the case of CdSe no such difference is found.