We show that there can be a contamination of silica particles on the surface of chemo-mechanically polished ZnO substrates. Consideration of the base of electrochemistry led us to a hypothesis that the alkaline polishing solution produces a layer of Zn(OH)2 capturing silica particles. In-situ observation of the etching process in an acidic solution by means of an atomic force microscope as well as zeta potential measurements supports this hypothesis and gives a clear guidance to solve the problem. We find that an epitaxy-ready surface can be reproducibly prepared by dipping ZnO substrates in an HCl solution (HCl : H2O = 7 : 200) for 30 s.
ASJC Scopus subject areas
- Physics and Astronomy(all)