HIGH-QUALITY SINGLE AND DOUBLE 2-DIMENSIONAL ELECTRON GASES GROWN BY METALORGANIC VAPOR-PHASE EPITAXY

We demonstrate the metalorganic vapor phase epitaxy (MOVPE) growth of AlGaAs/GaAs two-dimensional electron gases (2DEGs) with mobilities as high as 786 000 cm(2)/V s at a carrier density of 3.0X10(11) cm(-2) at 0.3 K. The mobility figures of merit (mu/n(3/2)) for these 2DEGs are the highest reported to date for MOVPE materials. These 2DEGs also exhibit the fractional quantum Hall effect (FQHE) with minima in longitudinal resistance corresponding to Landau level filling factors 2/3, 4/3, and 5/3. The temperature dependence and carrier density dependence of mobility were characterized, and the mobility was found to vary linearly with carrier density, implying that the mobility is probably limited by background ionized impurity scattering. A delta-doped 2DEG was also compared with uniformly doped 2DEGs and was found to have a slightly higher mobility. Finally, we obtained high mobility in a coupled double 2DEG structure for 2D to 2D tunneling applications. (C) 1995 American Institute of Physics.