Factors controlling resolution in the laser-induced aqueous etching of semiconductors using a focused cw beam

We present a study of selected factors which can control or improve the resolution of light-induced wet etching of semiconductors; specifically we examine the case of a focused Gaussian cw laser beam. The results have important implications for the recent application of the technique to the maskless fabrication of integrated optic device structures. Factors considered include semiconductor doping, solution composition, laser intensity, and the effect of applied bias. Results are discussed in the context of hole diffusion and drift in the semiconductor and transport through the solution/semiconductor interface.