Maskless Texture Etching of GaAs

Chemical etches to produce a low-reflectance textured surface on GaAs surfaces were investigated. The Caros etch at 1.3 ~ produced a fine (20 nm) random surface t xture on GaAs. Reduced optical reflectivity was seen, with the greatest reduction occurring at short wavelength. Texture etching is a technique commonly used to reduce surface reflection from semiconductors using an anisotropic etch. This pro-cess creates a surface structure in which incident light has several opportunities to be absorbed by the semiconductor. This is used, for example, to enhance the fficiency of a solar cell or a light detector. Texture etching is commonly used in processing silicon solar cells 1'2 but is not currently used for GaAs. While anisotropic etching has been demonstrated on GaAs solar cells, 3 the previously demonstrated technology for reflection reduc-tion by anisotropic etching on GaAs required masking the surface with photoresist stripes, to produce v-grooves. 3,4 This photoresis