Growth of molybdenum and tungsten on GaAs in a molecular beam epitaxy system

Thin films of Mo and W were grown on top of (100) GaAs in a molecular beam epitaxy system. Mo grew epitaxially between 200 and 450°C with its (111) plane parallel to (100) GaAs plane. W grew as a random polycrystalline deposit. For both metals, interaction with the GaAs occurred during growth at 500°C. Schottky barrier heights determined by current and capacitance measurements show that the electrical properties of the metal-GaAs interface do not strongly depend on the growth temperature and the microstructure of the films.