The study of nano-structure on in-situ UV laser irradiating GaAs(001) substrate

Abstract

The AFM study of a series of novel nano-structure on in-situ laser irradiating GaAs(001) substrate in molecular beam epitaxy was presented. Nano-hole, nano-island and nano-ring(Chinese ancient copper coin shape) were observed after laser irradiating. The desorption of Gallium on GaAs surface varies according to different power energy and pulse numbers, leading to the formation of nano-holes, nano-islands and nano-rings. It is speculated that these nanostructures are galliumrich through the change of the RHEED stripe. What’s more, the desorption of defectless GaAs sub-monolayer was discovered, and matched dynamic evolution model (self-drilling effect dominated by Ga atom) was presented. The dependence of the temperature on the surface of the substrate with time was studied after laser irradiating according to the heat conduction equation. The drastic temperature changes caused non-thermodynamic equilibrium process which makes these morphologies.