Improvement of structural and electronic properties of metamorphic InAs films on GaAs(111)A: Effects of growth temperature and insertion layers

We investigated the effects of insertion layers at the initial stage of growth on the crystalline and electrical properties of lattice-relaxed (metamorphic) InAs films grown on GaAs(111)A substrates. Introducing thin, low-temperature InAs layers at the initial stage, followed by high-temperature growth, led to a noticeable reduction in the peak width of the x-ray rocking curve (XRC) compared with samples grown at fixed (high) temperatures. By introducing hetero-material insertion layers, such as AlSb and InAs/InAlAs superlattice (SL), more pronounced changes were achieved. While the insertion of an AlSb layer realizes a large reduction in the XRC peak width, it also has undesirable effects, namely, an increase in the threading-dislocation density and a decrease in the electron mobility. The electron mobility was improved by the insertion of InAs/InAlAs SL, while the XRC peak width was not reduced.