Effects of trimethylantimonide/triethylgallium ratios on epilayer properties of gallium antimonide grown by low-pressure metalorganic chemical vapor deposition

Publisher Website
Google Scholar
Abstract
Undoped GaSb epitaxial layers were grown on (100) GaSb substrates by low-pressure metalorganic chemical vapor deposition. The trimethylantimonide/triethylgallium mole fraction (V/III) ratios were varied at a growth temperature of 600 °C and growth pressure of 100 Torr. It was found that the layer morphologies were strongly dependent on V/III ratios. The mirrorlike surface can be easily obtained under the V/III ratio in the range of 6–8. The growth rate was about 1.75 μm/h. The epitaxial layers were characterized by photoluminescence(PL) measurements and electron diffraction patterns. The bound-exciton peaks and strong acceptor band peak in the PL spectra were observed from the sample grown under a V/III ratio of 6.84. PL peak intensity was found to be a function of the V/III ratios. I-V characteristics of the p-n diodes fabricated on the sample of undoped GaSb/GaSb:Te was measured. The undoped acceptor carrier concentration and mobility were 9.47×1016 cm−3 (300 K), 1.60×1016 cm−3 (77 K), 275.3 cm2 /V s (300 K), and 491.6 cm2/V s (77 K), respectively.