Investigation of triethylarsenic as a replacement for arsine in the metalorganic chemical vapor deposition of GaAs

GaAs growth experiments have been performed with triethylarsenic (TEAs) to investigate its potential as a replacement for arsine, and to compare the effects on film properties of substituting ethyl for methyl groups in alkyl arsenic sources used in metalorganic chemical vapor deposition. Films were deposited over a wide range of growth conditions (Tg=550–750 °C, V/III=2–13), and data were obtained on film electrical and optical properties and variations in growth rate. Growth with TEAs yielded films with good surface morphology, low background doping levels (<1015 cm−3) and 77 K mobilities of 13 000 cm2/V s. Although this represents a considerable improvement over films grown with trimethylarsenic, film properties still appear to be limited by unacceptably high levels of carbon incorporation. Experiments using triethylgallium as the group III source in place of trimethylgallium resulted in substantially reduced and nonuniform growth due to prereaction at the reactor walls.