Excimer laser stimulated growth of polycrystalline GaAs films.

We report the growth of GaAs thin films by an excimer laser induced photodecomposition process. (CH(3)(3))Ga and As(CH (3)(3)) mixtures are photolyzed above Si and GaAs substrates by a 193 nm ArF excimer laser beam directed normal to the substrate surface. Gas-phase products diffuse to and stick on the surface where further laser irradiation leads to carbon removal and formation of GaAs. Films deposited on (100) Si and GaAs surfaces are polycrystalline, due to the low substrate temperatures (50-270C) and insufficient fluences on the surface (50 mJ/cm (2)) to promote mobility by transient laser annealing, and hence epitaxy. Evidence for enhanced deposition at low substrate temperature ( 100C) due to ad-layer photodecomposition has also been found.