Growth temperature dependence of transport properties of InAs epilayers grown on GaP

Undoped InAs was grown by molecular-beam epitaxy directly on GaP at a set o f different substrate temperatures. Transport properties were characterized by means of Hall-effect and resistivity measurements at temperatures betwe en 3 and 300 K. It was observed that samples grown at higher temperatures h ad lower carrier concentrations, consistent with a decrease of ionized defe cts. In addition, samples grown at higher temperatures also had higher mobi lity, consistent with a smaller number of scattering centers. Samples grown at higher temperatures also showed much higher sensitivity of the mobility to the measurement temperature, suggesting a drop in neutral scattering de fects. Transmission electron microscopy showed that the samples grown at hi gher temperatures had a significantly different dislocation microstructure. The observed dislocation microstructure is consistent with the mechanisms proposed for the influence of growth temperature on the variation of carrie r concentration and mobility. (C) 2000 American Institute of Physics. [S000 3-6951(00)01234-1].