We discuss the molecular beam epitaxial growth of the random alloy InAsSb for use as the channel 2/V S in high electron mobility transistors (HEMTs). Room-temperature mobilities of 22 000 cm(2)/V s have been achieved at a sheet carrier density of 1.4 X 10(12)/cm(2). This is a marked improvement over the mobility of 13 000 cm(2)/V s at the same carrier density obtained in previous attempts to grow the InAsSb channel using a digital alloy procedure [J. B. Boos, M. J. Yang, B. R. Bennett, D. Park, W. Kruppa, R. Bass, Electron. Lett. 35, 847 (1999)]. We have also, implemented different barriers and buffer layers to enhance the transport properties and overall performance of the HEMT structure.