Comprehensive scaling study of NbO2 insulator-metal-transition selector for cross point array application

Abstract

The transition metal oxide, NbO2, which exhibits an insulator to metal transition (IMT) is regarded as a promising selector device to be integrated with a resistive memory for cross point array application. In this study, we comprehensively investigated the scaling of an NbO2 selector using a mushroom device structure. A thorough understanding of the scaling behavior of forming voltage (Vf), threshold voltage (Vth), and current (Ith) is essential to evaluate the potential of voltage as well as current scaling and selectivity of NbO2 selector. Importantly, by analyzing the scaling trend of threshold current, we believed that the IMT behavior is strongly affected by filamentary conducting path formed during the forming process. The findings provide the promise to maximize the selector device performance by minimizing the conducting path inside the NbO2 layer.

A Strategy to Design High‐Density Nanoscale Devices utilizing Vapor Deposition of Metal Halide Perovskite Materials

“…However, a cross-point array with only ReRAMs has the problem of read failure due to sneak current. [46] Moreover, various selector materials have been developed, [47][48][49] so in the future selector devices may be integrated with the perovskite memory devices. To solve this problem, we could consider various device structures like one diode/one resistor (1D-1R) [45] or one selector/one resistor (1S-1R).…”

“…To solve this problem, we could consider various device structures like one diode/one resistor (1D-1R) [45] or one selector/one resistor (1S-1R). [46] Moreover, various selector materials have been developed, [47][48][49] so in the future selector devices may be integrated with the perovskite memory devices. Recently, there has been active research to develop solar cells and electronic devices utilizing inorganic perovskite materials.…”

The role of defects in the electrical properties of NbO2 thin film vertical devices

“…9 Reversible threshold switching in current has been reported mostly using amorphous NbO 2 films, where the current turns off immediately after lowering the input voltage (V in ) below the threshold voltage (V th ). 3,[10][11][12][13] Current-voltage (IV ) characteristics usually exhibit current-controlled (s-type) negative differential resistance (dV /dI < 0) while switching from a low current semiconducting to a high current metallic state. [14][15][16] Within the region of negative differential resistance, the current remains unstable and self-sustained current oscillations can be generated.…”

Progresses and outlook in neuromorphic devices

“…例如, 在基于TaO x / Ta 2 O 5 的二阶忆阻器中, 器件的温度可以看作影响器件 电导改变的隐变量, 通过施加脉冲序列调控器件内部 温度, 可实现时间编码的计算任务 [15] . [16] , 其结构为金属/ 相变材料/金属; 另一种是基于NbO 2 和VO 2 材料利用金 属到绝缘体的相变制成的莫特(Mott)器件 [17] , 其结构为 金属/氧化物/金属. 对于PCM, 晶态为高电导, 非晶态为 [11] , Copyright © Springer Nature; (d) 在透射电子显微镜下PCM器件相变过程 [16] , Copyright © AIP Publishing; (e) 在透射电子显微镜下NbO 2 莫特器件的结构 [17] , Copyright © AIP Publishing; (f) 莫特器件转变过程下的电子束衍射图 [18] , Copyright © Springer Nature Figure 1 (Color online) Characterization of the dynamic process occurring inside the device.…”

“…[16] , 其结构为金属/ 相变材料/金属; 另一种是基于NbO 2 和VO 2 材料利用金 属到绝缘体的相变制成的莫特(Mott)器件 [17] , 其结构为 金属/氧化物/金属. 对于PCM, 晶态为高电导, 非晶态为 [11] , Copyright © Springer Nature; (d) 在透射电子显微镜下PCM器件相变过程 [16] , Copyright © AIP Publishing; (e) 在透射电子显微镜下NbO 2 莫特器件的结构 [17] , Copyright © AIP Publishing; (f) 莫特器件转变过程下的电子束衍射图 [18] , Copyright © Springer Nature Figure 1 (Color online) Characterization of the dynamic process occurring inside the device. (a)−(c) Growth and dissolution of conductive filaments in the ion transfer device under the TEM [11] , Copyright © Springer Nature; (d) phase transition process in the PCM device under the TEM [16] , Copyright © AIP Publishing; (e) structure of NbO 2 Mott device under the TEM [17] , Copyright © AIP Publishing; (f) selected electron diffraction pattern in the transition process of the Mott device [18] , Copyright © Springer Nature 加的电学脉冲改变器件的等效电阻值并存储在器件中,…”