Morphology of patterned semiconductor III-V surfaces prepared by spontaneous anisotropic chemical etching

Abstract

In the present paper we report on scanning electron microscopy and atomic force microscopy study of different microreliefs obtained through a spontaneous anisotropic etching (that is without the use of masking, photochemical and photoelectrochemical techniques) of the surfaces of monocrystalline A$^{III}$B$^{V}$-type semiconductors: InP(100) doped with S and Fe, GaP(100), GaSb(100), InSb(100) and GaAs(100). The microrelief morphology (star-like, pyramides, grooves, etc.) depends on acidic etchant employed. Estimation of the activation energy demonstrates that the etching with microrelief formation occurs in the kinetic region. The most interesting InP microrelief is the two-dimensional groove-shaped one, which might be suitable to produce antireflection surfaces for solar cells. The conditions have been optimized to fabricate this microrelief with a given groove period of 0.6 to 3.7 $\mu $m. Morphology of different textured surfaces of other A$^{III}$B$^{V}$ semiconductors is also discussed.