AFM and XRD studies of GaAs surface after anisotropic etching
Abstract
A technology of anisotropic etching of GaAs (100) samples with two different types of geometric disorder (dendrite, quasi-grating) has been elaborated. The geometric statistical parameters of micro(nano)relief were investigated using bearing analysis. The measurements of the radii of curvature have shown that the samples were rather deformed, with nonuniform strain lateral distribution over the wafer areas. The radii of curvature were different for different samples, depending on surface treatment. The X-ray diffraction data indicate that the subsurface region of anisotropically etched GaAs crystal and epitaxial films grown on such substrates are not worse than those of a crystal with smooth chemically polished surface. Geometric disorder of such surfaces leads to enhancement of the diffuse contributions on the rocking curve tails.