Electrophysical and structural properties of the composite quantum wells In_(0.52)Al_(0.48)As/In_xGa_(1-x)As/In_(0.52)Al_(0.48)As with ultrathin InAs inserts

摘要

The electrophysical and structural properties of InAlAs/InGaAs/InAlAs quantum wells (QWs) with thin InAs inserts were investigated by means of Hall effect measurements and scanning transmission electron microscopy. The analyzed heterostructures are nearly the same ones using for high electron mobility transistors manufacturing except for heavily doped contact top layer. The increase of the electron mobility and concentration in the heterostructures with thin InAs layers in the center of the InGaAs QW as compared with the uniform QW was found and this effect strongly depended on the technological conditions during growth of the InAs inserts. The dependence of the InAs insert structural quality and heterointerface width on the As_4 beam equivalent pressure P_(As) was revealed. The decreased P_(As) is required for obtaining uniform and smooth InAs inserts as opposed to higher P_(As) resulting in the interface spreading and lateral composition inhomogeneity of the InAs insert.