ZnO is a wide bandgap semiconductor (3.37 eV) with large exciton binding energy (60 meV). For these reasons, it is a good material for applications in ultraviolet light-emitters and laser diodes. However, the UV applications are being impeded because obtaining p-type conductivity ZnO is still difficult. There are some papers, which report on successful preparation of ZnO p-type layers with sufficient electrical quality. This fact and unquestionable advantages of homoepitaxial growth, such as lack of stress in epitaxal layer and, in turn, low number of structural defects, motivated us to grow ZnO using the Atomic Layer Epitaxy technique. The easy access to ZnO substrates produced by CVT method also influenced our decision. ALE grown samples were analyzed using Atomic Force Microscopy. On the first obtained homoepitaxal ZnO layers we found regions of several square micrometers with good crystalline quality. This success encouraged us to continue growth and characterization experiments, which are presented in this work.

This work was supported by the Ministry of Science and Information Technologies, Poland, through the grant No. 3 T08A 051 28.