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 exh ibit the fractional quantum Hall effect (FQHE) with minima in longitud inal resistance corresponding to Landau level filling factors 2/3, 4/3 , and 5/3. The temperature dependence and carrier density dependence o f mobility were characterized, and the mobility was found to vary line arly with carrier density, implying that the mobility is probably limi ted by background ionized impurity scattering. A delta-doped 2DEG was also compared with uniformly doped 2DEGs and was found to have a sligh tly higher mobility. Finally, we obtained high mobility in a coupled d ouble 2DEG structure for 2D to 2D tunneling applications. (C) 1995 Ame rican Institute of Physics.