Hole mobility in AlxGa1−xSb grown by metalorganic chemical vapor deposition

Abstract

The temperature dependence of the hole mobilities of AlxGa1−xSb films in the regime 0⩽x⩽0.25 has been examined by Van der Pauw–Hall measurements. The films have been grown by metalorganic chemical vapor deposition on Si–GaAs substrates using TMAl, TMGa, and TMSb precursors. The mobility decreases sharply when a small amount of Al in the range 0<x<0.025 is incorporated into GaSb. The temperature dependence of mobility was analyzed using a model with contributions from various scattering mechanisms. At a low-temperature (<100 K), the mobility decreased due to a contribution from ionized-impurity scattering and in a high-temperature region (>100 K), the same effect was due to lattice phonon scattering. At 300 and 77 K, the alloy scattering is the most important mechanism in AlxGa1−xSb ternaries, however the temperature dependence of alloy scattering is less pronounced as the temperature decreases.