TRANSPORT MEASUREMENTS AND DONOR SPECTRA OF VERY HIGH-PURITY GAAS GROWN USING TERTIARYBUTYLARSINE AND TRIETHYLGALLIUM

Very high purity n-type GaAs epilayers were grown by low pressure meta lorganic chemical vapor deposition using triethylgallium and tertiaryb utylarsine (TBA) or arsine (AsH3). Peak Hall mobilities of 209 000 cm2 /V s at 45 K were observed for growth with TBA. Carrier concentration and mobility measurements down to liquid helium temperatures verified the high purity of these layers. Scattering mechanisms were determined by fits to the mobility data, and found to be in agreement with previ ous high purity GaAs studies. Donor identification was carried out usi ng magnetophotoluminescence spectroscopy. A comparison of the residual donor species for AsH3- and TBA-grown epilayers is presented. No evid ence of preferential n-dopant incorporation was observed for layers gr own with TBA.