Composition-selective photochemical etching of compound semiconductors

Abstract
Compound semiconductor materials differing only in the relative amounts of constituent atoms are very difficult to etch selectively using current chemical etching techniques. We have developed a photochemical etching process that solves this problem by utilizing the difference in band gap of GaAs1−xPx materials differing slightly in composition to produce a very high degree of etching selectivity between the materials. The concepts employed in this process have general applicability to other compound semiconductor material systems.