Lattice-Mismatched Growth and Transport Properties of InAlAs/InGaAs Heterostructures on GaAs Substrates

Abstract

We report on the lattice-mismatched growth of In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As modulation-doped heterostructures on GaAs substrates by molecular beam epitaxy. A buffer layer structure and its growth conditions were optimized. As a result, we obtained a sample with a mirrorlike surface which exhibits electron mobility of 10500 cm 2 /V·s and 48500 cm 2 /V·s at 300 K and 77 K, respectively. These values are comparable to those obtained in lattice-matched structures grown on InP substrates. To our knowledge, the room temperature mobility is the highest ever reported in a modulation-doped heterostructure grown on a GaAs substrate.