Site-selective chemical etching of GaAs through a combination of self-organized spheres and silver particles as etching catalyst

Microfabrication of the n-GaAs substrate surface was investigated by a combination of colloidal crystal templating, electroless plating and subsequent metal-assisted etching using noble metals as a catalyst. Ag and Cu nanosized particles were deposited site selectively to form metal-honeycomb patterns on GaAs using self-organized polystyrene spheres as a mask. By Ag-assisted etching, GaAs was effectively etched into a convex-array structure. Different anisotropic etching patterns were observed throughout the substrate after Ag-assisted etching, by changing the crystal-face orientation of n-GaAs from (1 0 0) to (1 1 1).