Effects of oxygen flow ratios and annealing on TiOx deposited by reactive magnetron sputtering

Titanium oxide (TiOx) thin films were deposited on Cu (111)/Ti/SiO2/Si substrates by direct-current reactive magnetron sputtering at 3-15% oxygen flow ratios, then annealed by vacuum at 650 degrees C for 40min. The morphology, phase, and resistive switching behaviors of the as-deposited and annealed TiOx thin films were analyzed by atomic force microscope (AFM), X-ray diffraction (XRD), and semiconductor parameter analyzer (SPA), respectively. The results of X-ray diffraction (XRD) showed that annealing TiOx caused crystal structure changes compared to the as-deposited TiOx film. From XRD, the as-deposited TiOx films were practically amorphous. In contrast, the distinct crystalline peaks of anatase and rutile phases was detected at 10 F-O2% by 650 degrees C annealing and exhibited stable and superior resistance switching behaviors due to deep-level emissions of oxygen vacancies in the rutile and anatase phases.