A GexSe1-x switch-only-memory technology through polarized atomic distribution

Ovonic threshold switching (OTS) materials that are frequently used with a resistor (1S1R) in memory devices have been found to show controllable and reversible memory properties, which could enable new memory architectures. Here, we examine the impact of composition on the polarity-dependent memory properties of Ge_xSe_1-x OTS materials and reveal that an increase in Se content results in a higher set voltage threshold (V_th), a lower reset current (I_RST), and a higher set energy. Specifically, Ge₅₆Se₄₄ demonstrates two distinct V_th of 5.1 and 3.8 V, which retain after annealing at 85 ℃ for one day. We fabricated Ge₅₆Se₄₄ into 1000 by 1000 cross-point pillar arrays and tested 100 of them. The results demonstrated that these Ge₅₆Se₄₄ devices show similar memory properties with a reset speed of 1 μs, a set speed of 50 ns, and an endurance of over 10⁵ cycles. Interestingly, the Ge₅₆Se₄₄ pillars' reset and set states could be attributed to polarized atomic distributions. By utilizing Ge_xSe_1-x, we demonstrate a true cross-point switch-only-memory technology and provide mechanistic insights for self-selecting OTS materials.