Uniformity, Linearity, and Symmetry Enhancement in TiO<sub><i>x</i></sub>/MoS<sub>2–<i>x</i></sub>O<sub><i>x</i></sub> Based Analog RRAM via S-Vacancy Confined Nanofilament
Dongdong Sun, Xudong Zhu, Shaochuan Chen, Haotian Fang, Guixu Zhu, Gongpeng Lan, Lixin He, Yuanyuan Shi
Abstract
Due to the stochastic formation of conductive filaments (CFs), analog resistive random-access memory (RRAM) struggles to simultaneously achieve low variability, high linearity, and symmetry in conductance tuning, thus complicating on-chip training and limiting versatility of RRAM based computing-in-memory (CIM) chips. In this study, we present a simple and effective approach using monolayer (ML) MoS 2 as interlayer to control the CFs formation in TiO x switching layer. The limited S-vacancies (S v ) in MoS 2– x O x interlayer can further confine the position, size, and quantity of CFs, resulting in a highly uniform and symmetrical switching behavior. The set and reset voltages ( V set and V reset ) in TiO x /MoS 2– x O x based RRAM are symmetric, with cycle-to-cycle variations of 1.28% and 1.7%, respectively. Moreover, high conductance tuning linearity and 64-level switching capabilities are achieved, which facilitate high accuracy (93.02%) on-chip training. This method mitigates the device nonidealities of analog RRAM through S v confined CFs, accelerating the development of RRAM based CIM chips.