Electrical Investigation of Carbon Intrinsically- Doped GaAs Layers Grown by Metalorganic Vapour Phase Epitaxy from TMGa and TBAs

In this work the possibility of controlling carbon intrinsic-doping in GaAs homoepitaxial layers grown by metalorganic vapour phase epitaxy (MOVPE) from the trimethyl-gallium (TMGa) and tertiary-buthylarsine (TBAs) precursors was evaluated via the analysis of transport properties as a function of the growth parameters and for two substrates mis-orientations; Hall effect measurements were performed on the samples as a function of temperature. Intrinsically p-doped GaAs layers were obtained with a hole concentration in the range (1014-1018) cm-3 and a corresponding RT mobility in the range (100-400) cm2/Vs. The simultaneous analysis of the Hall free hole density and Hall mobility yielded the effective doping level, the compensation ratio and the thermal ionisation energy of the acceptor impurity as a function of the growth parameters.