DOPING CHARACTERISTICS OF SI INTO MOLECULAR-BEAM-EPITAXIALLY GROWN INALAS LAYERS

We studied the doping characteristics of Si into molecular-beam epitaxially grown InAlAs layers for various growth conditions. The growth temperature and V/III beam flux ratio proved to play different roles in Si doping. The growth temperature affects the Si doping concentration, and the V/III flux ratio does the compensation ratio. At T(s) = 560-degrees-C, a rather high temperature for the growth of InAlAs layers, the Si doping concentration reached 150% as compared with growth at T(s) = 500-degrees-C. With increasing V/III flux ratio, on the other hand, electron mobility and donor concentration increased, suggesting a decreased compensation ratio. We also found a considerable number of electron trapping centers at a low-growth temperature of 400-degrees-C.