Surface processes of selective growth by atomic layer epitaxy

Characteristics and mechanisms, of the crystallographic selective growth by atomic layer epitaxy (ALE) and the localized ALE growth over the nanometer scale area, are discussed focusing on the surface process. The experimental results indicate that higher growth temperature, and longer hydrogen purge time after AsH3 supply, promote the crystallographic selectivity of GaAs ALE growth. The characteristics of the ALE selective growth include high crystallographic selectivity, and high uniformity in the nanometer scale. The mechanisms of ALE selective growth seem to be caused by the separate enhancement of As desorption process and the self-limiting mechanism of Ga precursor adsorption process on the GaAs surface.