Aqueous bromine etching of InP: a specific surface chemistry

The n -InP behaviour in HBr (0.1-1.0 M)/Br2 (1.25 × 10-2M) aqueous solutions is studied by AAS, XPS and SEM-FEG. Indium AAS-titrations of the HBr/Br2 solutions demonstrate that InP undergoes an etching mechanism whatever the HBr/Br2 formulation. The etching process is always linear with time but its rate depends on the HBr concentration. XPS analyses permit to link the apparent slow-down of the dissolution process when decreasing the HBr molarity from 1.0 M to 0.1 M to the presence of a mixed (In,P)ox oxide layer on the surface. Therefore, the dissolution process of InP in HBr/Br2 solution appears to be ruled by the surface chemical state (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)