Epitaxial growth of ZnO thin films on R-plane sapphire substrate by radio frequency magnetron sputtering

Abstract

ZnO thin films were deposited on a R-plane sapphire substrate. The effects of the thermal energy and the kinetic energy of the sputtered species on the growth of ZnO thin films were investigated. By varying the substrate temperature, chamber pressure, and radio frequency power, the structure of ZnO thin films was transformed from polycrystalline to epitaxial on R-plane sapphire substrates. High quality (110) ZnO epitaxial thin films were grown at the condition of 400 °C, 250 W, and 5 mTorr. According to reflection high energy electron diffraction and reflection electron microscopy observations, there were no double diffraction distortion and any other patterns. Its surface roughness observed by atomic force microscopy was about 27 nm.

Preparation and characterization of p-type semiconducting tin oxide thin film gas sensors

“…Except the unknown peak, the intensity and sharpness of the peak increase as the calcination temperature increases from 400 to 600°C, which is caused by enhanced mobility of the atoms at higher temperature. 17 The average crystallite size ͑D͒ of calcined tin oxide thin film is estimated using the Scherrer equation as follows: 18 …”

Characterization of luminescent properties of ZnO:Er thin films prepared by rf magnetron sputtering

“…However, more highly c-axis oriented ZnO:Er films were grown at 100 W rather than at 150 W, even though higher kinetic energy could be provided to the sputtered particles at 150 W. Excessive rf powers inversely contribute to the decrease in structural order of the films due to a couple of factors, which are the high deposition rate, the relative number of Zn to ZnO ions arriving at the substrates, and the energy of secondary electrons emitted from the target. 15,16 In our work, it could be concluded that 100 W rf power was an optimal condition, while 150 W was too much for high quality films.…”

p-type conduction from Sb-doped ZnO thin films grown by dual ion beam sputtering in the absence of oxygen ambient

“…Further rise in growth temperature resulted in the breaking of SZO bonds and consequent resputtering of the deposited film rather than enabling the atoms to move to their stable lattice sites, producing defects in the film, and thus degrading the crystalline property. 17 Moreover, XRD measurements of SZO films, as in Fig. 1(a), did not indicate any trace of Sb or its oxide (Sb 2 O 3 ) in SZO films.…”