Compliance current and film thickness influence upon multi-level threshold resistive switching of amorphous BaTiO3 (am-BTO) films in Ag/am-BTO/Ag cross point structures

The influence of compliance current and film thickness upon mull-level threshold resistive switching characteristics of amorphous BaTiO3 (am-BTO) thin films in Ag/am-BTO/Ag cross point structures have been investigated. The cross-point junctions are fabricated utilizing RF/DC magnetron sputtering technique and the thickness of am-BTO films are tuned with the sputtering time. The structural and microstructural details are probed with X-ray diffraction, Atomic force microscopy, Field effect scanning electron microscopy and X-ray photoelectron spectroscopy techniques. The current-voltage characteristics revealed a stable threshold resistive switching with maximum I-ON/I-OFF ratios of similar to 2 x 10(3) with low-threshold voltages and near zero voltage hold values are noted for 142 nm am-BTO thin film at 1 x 10(-4) A compliance current. The compliance current found to affect the bi-stability or mull-level resistance switching. The contribution of oxygen vacancies to the switching is elucidated from X-ray photoelectron spectroscopy measurements. Furthermore, the thickness effect on threshold resistive switching properties along with conduction mechanisms in lower and higher resistance states are discussed.