Characterization of high indium content metamorphic InGaAs/InAlAs modulation-doped heterostructures

We have studied electronic and structural characterizations of high indium content metamorphic InGaAs/InAlAs modulation-doped heterostructures. An imp roved low-temperature electron mobility of mu (e) = 5.45 x 10(5) cm(2) Vs i n [(1) over bar 1 0] was confirmed for a directed Hall-bar sample when Si-d oped InAlAs layer was slightly etched. In addition, inplane mobility anisot ropy of 40% between [(1) over bar 1 0] and [1 1 0] directions. We confirmed . This anisotropy seems to br originated fi om the different undulation per iod between[(1) over bar 1 0] and [1 1 0] directions. We theoretically calc ulated electron mobility taking both alloy disorder scattering and backgrou nd impurity scattering into account. It is found that the calculated and ex perimental values are in good agreement. (C) 2001 Elsevier Science B.V. All rights reserved.