Transport in modulation-doped structures (AlxGa1−xAs/GaAs) and correlations with Monte Carlo calculations (GaAs)

Abstract
Electron velocity and mobility versus electric field measurements were made in AlxGa1−xAs/GaAs modulation‐doped structures in an electric field range of 0–2 kV/cm and in a temperature range of 77–300 K. The electron velocities obtained at 2 kV/cm were 1.7×107 cm/ s at 300 K and 2.24×107 cm/s at 77 K. The velocity‐field and mobility‐field characteristics obtained were in very good agreement with Monte Carlo results for undoped GaAs, suggesting that existing Monte Carlo calculations are capable of predicting transport in AlxGa1−xAs/GaAs modulation‐doped structures. An ideal modulation‐doped structure can thus be assumed to exhibit transport properties identical to that of undoped GaAs. The advantage of modulation doping is the ability to place 7×1011 cm−2 electrons at the heterointerface for current conduction for devices, while avoiding all the adverse effects of impurity scattering.