Improved multilevel storage capacity in Ge_(2)Sb_(2)Te_(5)-based phase-change memory using a high-aspect-ratio lateral structure  

通过高长宽比横向结构的设计提升基于Ge2Sb2Te5材料的相变存储器的多值存储能力

作　　者：Ruizhe Zhao Mingze He Lun Wang Ziqi Chen Xiaomin Cheng Hao Tong Xiangshui Miao 赵锐哲;何明泽;王伦;陈子琪;程晓敏;童浩;缪向水(Wuhan National Laboratory for Optoelectronics,School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;Hubei Yangtze Memory Laboratories,Wuhan 430205,China)

机构地区：[1]Wuhan National Laboratory for Optoelectronics,School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China [2]Hubei Yangtze Memory Laboratories,Wuhan 430205,China

出　　处：《Science China Materials》2022年第10期2818-2825,共8页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(62174065);the Key Research and Development Plan of Hubei Province(2020BAB007);Hubei Provincial Natural Science Foundation(2021CFA038);the support from Hubei Key Laboratory of Advanced Memories&Hubei Engineering Research Center on Microelectronics。

摘　　要：Further improvement of storage density is a key challenge for the application of phase-change memory(PCM)in storage-class memory.However,for PCM,storage density improvements include feature size scaling down and multilevel cell(MLC)operation,potentially causing thermal crosstalk issues and phase separation issues,respectively.To address these challenges,we propose a high-aspect-ratio(25:1)lateral nanowire(NW)PCM device with conventional chalcogenide Ge_(2)Sb_(2)Te_(5)(GST-225)to realize stable MLC operations,i.e.,low intra-and inter-cell variability and low resistance drift(coefficient=0.009).The improved MLC performance is attributed to the high aspect ratio,which enables precise control of the amorphous region because of sidewall confinement,as confirmed by transmission electron microscopy analysis.In summary,the NW devices provide guidance for the design of future high-aspect-ratio threedimensional PCM devices with MLC capability.如何进一步提高存储密度是相变存储(PCM)应用于存储级内存(SCM)的关键挑战.然而,相变存储器主要通过尺寸微缩和多值操作来提高存储密度,往往面临严重的热串扰和相分离问题.为此,我们提出了一种高长宽比(25:1)的横向纳米线器件,该器件采用传统的硫系化合物Ge_(2)Sb_(2)Te_(5)就可以实现稳定的多值操作,并且器件具有较好的一致性以及较低的电阻漂移系数(0.009),其优异的多值性能主要是由于在设计的高长宽比结构中,绝缘层侧壁的限制使得相变材料的非晶区域可以精确控制,这也被透射电子显微镜分析证实.本文设计的纳米线器件为提升高深宽比三维相变存储器的多值存储能力提供了重要指导.

关 键 词：multilevel cell high aspect ratio NANOWIRES 3D phase-change memory Ge_(2)Sb_(2)Te_(5) 

分 类 号：TB34[一般工业技术—材料科学与工程] TP333[自动化与计算机技术—计算机系统结构]