Undoped high mobility two-dimensional hole-channel GaAs/AlxGa1-xAs heterostructure field-effect transistors with atomic-layer-deposited dielectric

The authors have fabricated undoped p-channel GaAs/AlxGa1-xAs heterostructure field-effect transistors with nearly ideal drain current-voltage characteristics, using atomic-layer-deposited Al2O3 as the dielectric, and measured their transport properties. At 0.3 K, the densities and mobilities of the two dimensional holes can be tuned up to 2.9x10(11)/cm(2) and 6.4x10(5) cm(2)/V s, respectively. The variable density high mobility two-dimensional hole system provides a large parameter space for the study of two-dimensional physics. (c) 2007 American Institute of Physics.