Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, China.
University of Science and Technology Beijing, Beijing, 100083, China.
Sci Rep. 2017 Sep 11;7(1):11204. doi: 10.1038/s41598-017-11165-5.
In resistive random access memories, modeling conductive filament growing dynamics is important to understand the switching mechanism and variability. In this paper, a universal Monte Carlo simulator is developed based on a cell switching model and a tunneling-based transport model. Driven by external electric field, the growing process of the nanoscale filament occurring in the gap region is actually dominated by cells' conductive/insulating switching, modeled through a phenomenological physics-based probability function. The electric transport through the partially formed CF is considered as current tunneling in the framework of the Quantum Point Contact model, and the potential barrier is modulated during cells' evolution. To demonstrate the validity and universality of our simulator, various operation schemes are simulated, with the simulated I - V characteristics well explaining experimental observations. Furthermore, the statistical analyses of simulation results in terms of Weibull distribution and conductance evolution also nicely track previous experimental results. Representing a simulation scale that links atomic-scale simulations to compact modeling, our simulator has the advantage of being much faster comparing with other atomic-scale models. Meanwhile, our simulator shows good universality since it can be applied to various operation signals, and also to different electrodes and dielectric layers dominated by different switching mechanisms.
在电阻式随机存取存储器中,对导电细丝生长动力学进行建模对于理解开关机制和变异性非常重要。本文基于单元开关模型和基于隧穿的输运模型开发了一种通用的蒙特卡罗模拟器。在外电场的驱动下,纳米尺度细丝在间隙区域的生长过程实际上由单元的导电/绝缘转变主导,通过基于唯象物理的概率函数来建模。通过量子点接触模型考虑部分形成的 CF 的电输运,并且在单元演化过程中调制势垒。为了验证我们的模拟器的有效性和通用性,模拟了各种操作方案,模拟的 I-V 特性很好地解释了实验观察结果。此外,基于威布尔分布和电导演化的模拟结果的统计分析也很好地跟踪了以前的实验结果。作为连接原子尺度模拟和紧凑模型的模拟尺度,我们的模拟器具有与其他原子尺度模型相比更快的优势。同时,由于它可以应用于各种操作信号,以及由不同开关机制主导的不同电极和介电层,因此我们的模拟器具有很好的通用性。