Investigation of ZnO films on Si⟨111⟩ substrate grown by low energy O+ assisted pulse laser deposited technology

Zinc oxide thin films (ZnO) with different thickness were prepared on Si (111) substrates using low energy O+ assisted pulse laser deposition (PLD). The structural and morphological properties of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements, respectively. The quality of ZnO films was also examined by using Rutherford backscattering spectroscopy/ion channeling (RBS/C) techniques. XRD showed that there was only one sharp diffraction peak at 2 theta = 34.3 degrees with the full width at the half maximum (FWHM) of around 0.34 degrees for two ZnO samples, which also indicated that ZnO thin films had a good c-axis preferred orientation. Results of Rutherford backscattering and ion channeling clearly indicated that the Zn:O ratio in zinc oxide thin film approached to unity and the ZnO thin film grown by low energy O+ assisted pulse laser deposition had a polycrystalline structure. In the case of ZnO film fabricated by low energy O+ assisted pulse laser deposited under identical experimental conditions except growth time, AFM analysis has shown that the root mean square (RMS) roughness (2.37 nm) of thinner ZnO film (3 5 nm) was far below that (13.45 nm) of the thicker ZnO film (72 nm). (c) 2006 Elsevier B.V. All rights reserved.