Galvanomagnetic properties of recrystallized dendritic InSb films

Abstract

The galvanomagnetic properties of monophase, dendritic, preferentially oriented InSb films grown from a non-stoichiometric melt containing an excess of Sb, are described. Such films are n-type and have the following properties: a Hall coefficient of the same order of magnitude as that of bulk polycrystalline InSb, an electron mobility which is thickness dependent reaching a value μ e = 4 × 10 4 cm 2/V-sec in films 3 μm thick, a magnetoresistance which is quadratic in H for μH < 1 and is linear in H for μH > 1, inhomogeneity fluctuations and resistivity striations which lead to geometrical effects larger than those associated with macroscopic length to width ratios of rectangular specimens. The charge carrier density in these films is between 5 × 10 16 electrons/cm 3 and 2 × 10 16 electrons/cm 3 near 300°K. Experimental data suggests that lattice scattering, in combination with dislocation scattering in accordance with the Dexter-Seitz model, accounts for the temperature dependence of the electron mobility above 200°K. Calculated dislocation densities in films are of the order of 10 9. It is suggested that dislocation scattering represents a significant mobility limiting process in evaporated or recrystallized InSb films.