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Modulating the growth conditions: Si as an acceptor in (110) GaAs for high mobility p-type heterostructures

F. Fischer·M. Grayson·D. Schuh·M. Bichler·G. Abstreiter
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Abstract

We implement metallic layers of Si-doped (110) GaAs as modulation doping in high mobility p-type heterostructures, changing to p-growth conditions for the doping layer alone. The strongly auto-compensated doping is first characterized in bulk samples, identifying the metal-insulator transition density and confirming classic hopping conduction in the insulating regime. To overcome the poor morphology inherent to Si p-type (110) growth, heterostructures are fabricated with only the modulation doping layer grown under p-type conditions. Such heterostructures show a hole mobility of 1.75x10^2 cm^2/Vs at density p=2.4x10^11 cm^-2. We identify the zero field spin-splitting characteristic of p-type heterostructures, but observe a remarkably isotropic mobility and a persistent photoconductivity unusual for p-heterojunctions grown using other doping techniques. This new modulated growth technique is particularly relevant for p-type cleaved-edge overgrowth and for III-V growth chambers where Si is the only dopant.

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F. Fischer, M. Grayson, D. Schuh, M. Bichler, G. Abstreiter. 2004-11-29. Modulating the growth conditions: Si as an acceptor in (110) GaAs for high mobility p-type heterostructures. https://doi.org/10.1063/1.1923761

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