Properties of ZnO Thin Films Grown on Si (100) Substrates by Pulsed Laser Deposition

ZnO thin films were grown on Si (100) substrates by pulsed laser deposition using a ZnO target. The substrate temperature was varied in the range of room temperature to 800°C, and the oxygen partial pressure of 0.1333 Pa (1 mTorr) to 1333 Pa (10 Torr). The properties of the resulting films were investigated by photoluminescence (PL), grazing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM). Based on the ultraviolet (UV, ∼380 nm) to visible emission ratio in the PL spectrum, the optimum growth conditions were determined to be 600°C and 133.3 Pa (1 Torr), respectively. The oxygen 1s peak in the XPS spectrum was decomposed into two peaks. The peak at lower binding energy increased in intensity with the oxygen partial pressure from 0.1333 Pa (1 mTorr) to 133.3 Pa (1 Torr) while the other peak decreased. The GIXRD curve at the optimum condition showed strong two peaks (002 and (103). A strong correlation between the (103) peak intensity and the UV emission intensity was found.