Corrosion Behavior and Surface Studies of GaAs in Acidic
C.A. Steer, J.L. Luo and D.G. Ivey
Dept. of Chemical and Materials Engineering, University of Alberta
Edmonton, Alberta, T6G2G6. Canada
The corrosion behavior of GaAs in various acid solutions and deionized water was studied. Potentiodynamic polarization measurements show that the factors promoting the generation of holes, or the injection of holes from the solution to the valence band, will increase the tendency of the semiconductor towards active dissolution.
During anodic polarization of n- and p-GaAs in acids, air-formed As and Ga oxides are both dissolved. The GaAs substrate is also dissolved and significant anodic segregation occurs leaving an As-rich surface layer, which gradually agglomerates and oxidizes for form As2O3 particle formation occurs. Polarization of GaAs indeionized water did not remove the surface film; instead the oxide layer thickened without the formation of As2O3 particles.