Behavior of a GaSb (100) Surface in the Presence of H2O2 in Wet-Etching Solutions

Gallium antimonide (GaSb) has an extremely high electron mobility and an excellent lattice match with various III–V ternary and quaternary compounds. In this study, the effect of wet-etching processes on the GaSb (001) surface was investigated, with a focus on the effect of H 2 O 2 . Dilution with H 2 O and addition of H 2 O 2 in HF/H 2 O 2 /H 2 O, NH 4 OH/H 2 O 2 /H 2 O, and HCl/H 2 O 2 /H 2 O mixtures produced different effects on the GaSb surface. The etching rate of GaSb increased with a high dilution ratio and a small amount of H 2 O 2 in the mixture of NH 4 OH/H 2 O 2 /H 2 O. The addition of H 2 O 2 in H 2 O decreased GaSb oxide thickness and increased the contact angle on the GaSb surface and the XPS Ga 3d and Sb 3d 3/2 peak area ratios of Ga 2 O 3 /GaSb and Sb 2 O 3 /GaSb, which strongly imply that the H 2 O 2 in the wet-etching solution served as an inhibitor of surface oxidation on GaSb. On the basis of the observed etching rates of GaSb, oxidation kinetics, contact angles, and chemical states, it is suggested that concurrent oxidation of GaSb and etching of oxidized GaSb occur on the GaSb surface in the presence of H 2 O 2 . Furthermore, the overall kinetics is determined by the relative amount of H 2 O 2, which depends on the pH of the etching solution.