Study on the resistive switching behaviors of TiO₂ thin films by pulsed laser deposition

The TiO₂ thin films with resistive switching behaviors were grown on Pt (111)/Ti/SiO₂/Si substrates by pulsed laser deposition (PLD). Scanning electrical microscope (SEM) and atomic force microscope (AFM) were employed to characterize the as-grown films respectively. No evident diffraction peak of TiO₂ is found in X-ray diffraction (XRD) pattern. The films exhibit nanocrystalline or noncrystalline. The results show that the surfaces of the films are flat, smooth and dense. The results of electrical test indicate that TiO₂ thin films show a unipolar resistive switching behavior, and the high-resistance to low-resistance ratio can reach 10⁴. The electrical conduction of the films at high resistance state is controlled by the space charge limited current mechanism, and the soft-set phenomenon is found. The formation and rupture of conducting filaments in TiO₂ thin films are preliminarily analyzed.