Indium arsenide films grown on aluminum oxide ceramic

Polycrystalline indium arsenide films have been grown on ceramic substrates using a chemical vapor transport technique. Proper temperature control during the heating portion of the growth cycle and a coplanar arrangement of the source and substrate promote the initial nucleation of the film growth. To obtain a high electron mobility in the films a large crystal size is required. This can be achieved by adjusting the heating rate. The film with the largest crystals, approximately 3 μm, and a thickness of 6·9 μm had a Hall mobility of 12,300 cm²/V sec at 1 kG and 295°K. These films generally have higher mobility than those obtained by vacuum evaporation. The Hall mobility is limited by film inhomogeneities as determined from temperature plots of mobility and of Hall coefficient, along with an analysis of the scattering mechanisms, crystal size, and magnetoresistance of the films.