The Co-Improvement of Selectivity and Uniformity on NbOₓ-Based Selector by Al-Doping

Selectivity and uniformity are the stuck issues for the NbO
_x
–based selectors applied in memory arrays. In this letter, we experimentally demonstrated that the selector through Al-doping had significant improvement of selectivity (250%) and uniformity (from 4% to 1%). To understand the physical mechanism, the thermoelectric coupling model was employed. It was simulatively illustrated that lower OFF current and higher selectivity were induced by the increase of the Schottky barrier height and Schottky distance. Meanwhile, the ability of constraining oxygen vacancies reduced the random immigration, which contributed to a better uniformity. This study provided an effective way to improve the performance of the selectors and overcome the barrier in the application of 3D integrated memory.