The performance of the multi-layer NbOx selector is shown in Fig. 3, which indicates that CA-074 Me the Ith and Ioff are lowered by about 3 times and 5 times, respectively, compared to those of single-layer NbOx. In addition, the on/off ratio (selectivity) improved over 5 times by introducing the insulating barrier layer.
Fig. 3. The brief performances are arranged as a table.Figure optionsDownload full-size imageDownload as PowerPoint slide
The leakage current on the thin film is triggered by local “structural defects” (Fig. 4-(a)). The structural defects include various defects on thin film such as grain boundary, local amorphous state and non-stoichiometry phases. Unexpected structural defects can elevate the leakage current. It is found radioactive decay the non-stoichiometry phases of MIT material (such a VO2−x material), which has more oxygen vacancies (oxygen deficient phase), have lower conductivity than well matched stoichiometry film ,  and . Moreover, research, using C-AFM, revealed that the local amorphous state in polycrystalline thin-film and the grain boundaries can cause leakage current, especially with large defect density  and .