Au-catalyzed desorption of GaAs oxides.

Thermal desorption of native oxides on GaAs(100), (110) and (111)B surfaces around Au particles are studied in vacuum using in situ microspectroscopy. Two temperature-dependent desorption regimes, common to all surfaces, are identified. The low-temperature desorption regime spatially limited to the vicinity of some Au nanoparticles (NPs) is catalytically enhanced, resulting in oxide pinholes which expand laterally into macro holes many times the size of the catalyzing NPs and with shapes dictated by the underlying crystallography.