The thermal treatment effects of CrN buffer layer on crystal quality of Zn-polar ZnO films

We report on the annealing effects of CrN buffer layers on the crystal quality of Zn-polar ZnO films grown by plasma assisted molecular beam epitaxy. The high-temperature (HT) annealing of CrN buffer layer improved the crystallinity of ZnO films. The full width at half maximums of (0002) and (10-11) ZnO ω-scan X-ray diffraction show 574 and 1296 arcsec, respectively, which show the 3 and 2 times narrower values than those of ZnO films without the annealing process. Moreover, the HT annealing can be effective method to improve the surface smoothness of ZnO film and reduce the crystal tilting.