This paper presents experiments that examined the formation of the InAs/AlSb interface in high electron mobility transistor (HEMT) devices grown by molecular beam epitaxy (MBE). At the interface, indium barrier thickness and substrate temperature were varied. Reflection-high-energy-electron-diffraction (RHEED) intensity oscillations of the specular spot were recorded during formation of the interface. Electron mobility models based on growth conditions and RHEED data were developed using neural networks. Our results demonstrate a correlation of the electron mobility with growth conditions and RHEED data. (C) 2002 Elsevier Science Ltd. All rights reserved.