Preparation and Properties of Boron Arsenide Films

Boron arsenide films have been deposited on the basal plane of hexagonal silicon carbide and {111} oriented sodium fluoride and silicon substrates at 800°–850°C by the thermal decomposition of a diborane‐arsine mixture in a hydrogen atmosphere. Adherent films were deposited on silicon carbide substrates and were identified by electron diffraction as boron arsenide with random orientations. Boron arsenide deposits on sodium fluoride substrates were not adherent due to the large differences in their thermal expansion coefficients. Boron arsenide films deposited on silicon substrates were found to be amorphous by electron diffraction. Optical absorption measurements implied that boron arsenide is a direct gap material with a room temperature energy gap of about 1.45 eV. The current‐voltage characteristics of metal‐boron arsenide‐silicon structures have indicated that the current‐controlling mechanism is similar to that of an insulator containing traps of uniform energy. The density of traps was calculated to be approximately .