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

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 preve nt two-dimensional to three-dimensional transition at the InAlAs/InAs heter ointerface. Using a thick (7 nm) strained InAs layer as a channel, we simul taneously achieved a high electron mobility of 18 500 cm(2),Ns and a high s heet carrier density of 3.13 x 10(12) cm(-2) in the modulation doped struct ure on InP substrate. (C) 1999 Elsevier Science B.V. All rights reserved.