A new growth method has been developed for the atomic layer epitaxy of GaAs. The gas system was based on a conventional metalorganic vapor phase epitaxial system but the decomposition of methylgallium was suppressed in the stagnant layer by using a fast pulsed gas stream from a jet nozzle. The method enabled us to grow high purity epitaxial layers with a clear self-limiting mechanism even at 560 °C. The variations in the growth rate with respect to various growth parameters were explained by the rate equations based on the selective adsorption of methylgallium on surface As atoms. The decomposition rate of methylgallium on the surface had an activation energy of 42 kcal/mole from 440 to 560 °C.

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We carried out an in situ investigation of GaAs grown by atomic layer epitaxy, using an x-ray photoelectron spectroscopy system combined with a metalorganic vapor phase epitaxial growth chamber, where Ga(CH3)3 and AsH3 were the source gases. It has been proved that Ga(CH3)n molecules (where n=1 or 2) are decomposed into Ga atoms after being adsorbed on the GaAs surface around 500 °C. This means that the self-limited adsorption of Ga in the atomic layer epitaxy of GaAs can be achieved on the surface where the Ga adsorbate is atomic Ga.