DOPANT DISTRIBUTION FOR MAXIMUM CARRIER-MOBILITY IN SELECTIVITY DOPED Al sub (.30) Ga sub (.70) As/GaAs HETEROSTRUCTURES.
01 January 1989
The magnitude of potential fluctuations due to remote ionized dopants is calculated for selectivity doped heterostructures using unscreened screened Coulomb-potentials. Potential fluctuations are found to be minimized (corresponding to maximum carrier- mobility) if the dopant-distribution is delta-function-like. Our experimental study of electron-mobilities in selectivity doped heterostructures grown by molecular-beam epitaxy reveals that carrier-mobility indeed increases as the thickness of the doped layer is reduced, in agreement with the calculation. A peak electron-mobility of 5.5 x 10 sup 6 cm sup 2 /Vs is obtained at low temperatures in a selectivity doped heterostructure in which a delta-function-like doping profile is employed.