Study of PbSe layer oxidation and oxide dissolution

The presence of contamination at the Pb/p-PbSe interface corresponding to a Schottky contact leads to the formation of an n-type inversion layer resulting in an ohmic behaviour. In this work, the PbSe oxidation kinetics by air exposure is studied using XPS and AES measurements. We found that an oxide layer is formed at the surface, containing PbO and SeO2 compounds. Secondly, the oxide layer dissolution in KOH-based solutions is investigated. A C- and O-decontaminated PbSe surface is obtained after a few minutes soaking in a bath containing ethylene glycol as solvent. Anger microanalysis demonstrates that the decontaminated surface is made of PbxSe with x < 1, corresponding to a lead deficit. The surface morphology does not appear to be modified, as seen by AFM, but the root mean square roughness calculation shows a weak improvement. (C) 1999 Elsevier Science B.V. All rights reserved.