Highly conductive GaAsNSe alloys grown on GaAs and their nonalloyed ohmic properties

Doping properties of Se in GaAsN alloys grown on GaAs (001) substrates by m etalorganic-molecular-beam epitaxy were studied. Ditertiarybutylselenide (D tBSe) precursor was used as a Se source. It was found that Se was incorpora ted into GaAs and GaAsN layers up to a considerable concentration of simila r to 15%. It was also suggested that the N concentrations in GaAsNSe layers were increased by the DtBSe supply. The GaAsNSe layers were heavily doped n type, and the maximum electron concentration was as high as similar to 1x 10(20) cm(-3). With the increase of the carrier concentrations, the resisti vity of GaAsNSe dramatically decreased to 1.2x10(-4) Omega cm. This made it possible to have ohmic contacts without thermal annealing, which indicates that GaAsNSe alloys are an attractive candidate for the formation of nonal loyed ohmic contacts. (C) 2001 American Institute of Physics.