Towards clean and atomically flat ZnO (000&1macr;) surfaces

Abstract

We established a cleaning procedure to obtain atomically flat (000 1) surfaces from pressurized melt grown ZnO using ex-situ and in-situ processing. The ex-situ chemical cleaning consisted in removing the surface fluid layer and contaminants from the surface. The physical in-situ procedure used sputteringannealing cycles to clean and reconstruct the surface. 3 key parameters were in-situ investigated: the annealing time, the annealing temperature and the sputtering energy. Investigations were carried out by