Growth, etching, doping and effects of Ar + laser irradiation in chemical beam epitaxy of GaAs with novel precursors

Abstract

Tris-dimethylaminoarsenic (TDMAAs) is shown to be a viable alternative to arsine. With Ar ion laser irradiation, the growth enhancement at low substrate temperatures, compared to using arsine or arsenic, has a wider temperature range by ∼ 100°C, indicating a photochemical effect in addition to the photothermal effect. Furthermore, TDMAAs can be used to etch GaAs at a higher temperature by amine radicals as cracked TDMAAs has no etching effect. The etch rate can be enhanced by Ar ion laser irradiation through local heating. Smooth surface morphology in selective-area growth can be obtained with cracked TDMAAs. Diiodomethane is also shown to be a viable carbon-doping source, and laser-enhanced doping has a photochemical component as well. With cracked TDMAAs, a high 10 19 cm −3 hole concentration can be obtained.