Selected Area Growth of GaAs by Laser Induced Pyrolysis of Adsorbed Triethylgallium.

We report selected area growth of GaAs by XeF excimer laser induced pyrolysis of triethylgallium (TEGa) adsorbed on GaAs (100). TEGa dissociatively chemisorbs at 400C to form a stable layer which decomposes further under laser irradiation to liberate hydrocarbon products. The Ga left behind on the surface reacts with As sub 2 and As sub 4 (formed by pyrolysis of trimethlyarsine or triethylarsine in a side tube) to grow GaAs in irradiated areas. Patterned films with feature sizes of ~70microns (limited by the mask dimensions) were grown by this method. Interference between the incident beam and light scattered along the surface also causes a substructure of parallel lines to form on the features with a line spacing about equal to the laser wavelength 0.35microns. This indicates that the ultimate spatial resolution is comparable to that predicted by thermal diffusion calculations (~0.3microns).