SULFUR DOPING OF GAAS AND GAINP GROWN BY METALORGANIC MOLECULAR-BEAM EPITAXY USING A HYDROGEN-SULFIDE GASEOUS SOURCE

We report in this letter the sulfur doping of GaAs and Ga0.5In0.5P layers grown by metalorganic molecular beam epitaxy using a 1000 ppm hydrogen sulfide diluted in hydrogen dopant source. No precracking of H2S molecules is necessary to achieve efficient doping. The n-type doping level of both GaAs and Ga0.5In0.5P is proportional to the input H2S flow rate. Maximum doping levels of 8 X 10(17) and 3 X 10(18) cm-3 are measured in GaAs and Ga0.5In0.5P, respectively, with no saturation in either material within the doping range investigated. The doping level decreases as the growth temperature increases, with activation energies of 1.5 and 1.7 eV for GaAs and Ga0.5In0.5P, respectively. The sulfur incorporation decreases on increasing the V/III ratio in GaAs. The opposite behavior occurs in Ga0.5In0.5P.