Influence of rapid thermal annealing on structure and interfacial characteristic of ZnO thin films

Abstract

Highly C-axis oriented ZnO thin film was manufactured by radio-frequency magnetron sputtering technique on Si (111) substrate. The main objective was to study the influence of rapid thermal annealing (RTA) temperature on the structure and interfacial characteristic of ZnO thin films. X-ray diffraction results showed that the ZnO thin films annealed at 600 C by RTA technique had a perfect C-axis preferred orientation compared to the other ZnO thin films, and the full width at half maximum of ZnO (002) rocking curve measurements indicted that the RTA-annealed ZnO thin films possessed better crystal structure. Atom force microscopy displayed that the grain size of RTA-annealed ZnO thin films was fine and uniform compared with the as-deposited ZnO thin films, although the grains grew in RTA process and the root meant square roughness was smaller than that of as-deposited films. High-resolution transmission electron microscopy showed that there was an obvious amorphous layer between ZnO thin films and Si substrate, but the RTA-annealed ZnO thin films exhibited larger and denser columnar structure and a preferred orientation with highly c axis perpendicular to the amorphous layer.