Modulation doped structure with thick strained InAs channel beyond the critical thickness

Abstract

We successfully realized a modulation-doped structure on InP substrate with a thick strained InAs channel, which was twice thicker than the previously reported critical thickness. In our structure, an AlAs layer was inserted between an InAlAs spacer layer and the thick strained InAs channel to prevent two-dimensional to three-dimensional transition at the InAlAs/InAs heterointerface. Using a thick (7 nm) strained InAs layer as a channel, we simultaneously achieved a high electron mobility of 18 500 cm 2/Vs and a high sheet carrier density of 3.13×10 12 cm −2 in the modulation doped structure on InP substrate.