Large-area growth of vertically aligned ZnO pillars by radio-frequency magnetron sputtering

A new method for fabricating large-area well-aligned ZnO pillars, solely using radio-frequency magnetron sputtering, is reported. A mixture of argon and hydrogen gases was used as the plasma source, acting as a reduction agent. The ZnO pillars grow from a ZnO buffer layer with a ZnMgO nucleation stabilization layer on top, with the sputtered targets sharing the same composition. The entire growth is well controlled and linear. A shadowing effect is also responsible for the growth. The characteristics of the developed method are high uniformity and reproducibility, as commonly known for sputtering, which are vital prerequisites for future developments of nanodevices.