Anodic oxidation of InP in KOH electrolytes
Buckley, D. Noel
Cunnane, V. J.
Newcomb, Simon B.
The anodic behavior of InP in 1 mol dm-3 KOH was investigated and compared with its behavior at higher concentrations of KOH. At concentrations of 2 mol dm-3 KOH or greater, selective etching of InP occurs leading to thick porous InP layers near the surface of the sustrate. In contrast, in 1 mol dm-3 KOH, no such porous layers are formed but a thin surface film is formed at potentials in the range 0.6 V to 1.3 V. The thickness of this film was determined by spectroscopic ellipsometry as a function of the upper potential and the measured film thickness corresponds to the charge passed up to a potential of 1.0 V. Anodization to potentials above 1.5 V in 1 mol dm- 3 KOH results in the growth of thick, porous oxide films (~ 1.2 µm). These films are observed to crack, ex-situ, due to shrinkage after drying in ambient air. Comparisons between the charge density and film thickness measurements indicate a porosity of approximately 77% for such films.
Transmission electron microscopy , Spectroscopic ellipsometry , Anodization , Porous oxide films
O’Dwyer, C., Melly, T., Harvey, E., Buckley, D. N., Cunnane, V. J., Sutton, D., Serantoni, M. and Newcomb, S. B. (2002) 'Anodic Oxidation of InP in KOH Electrolytes', State-of-the-Art Program on Compound Semiconductors XXXVII (SOTAPOCS XXXVII) / Narrow Bandgap Optoelectronic Materials and Devices, 202nd ECS Meeting, Salt Lake City, Utah, 20-24 October, in Proceedings - Electrochemical Society, Vol. 14, pp. 233-240. ISBN 1-56677-306-5.
© 2002, Electrochemical Society