Strain Engineering for High-Performance Phase Change Memristors

• Published in: arXiv.org
• Main Authors: Hou, Wenhui, Azizimanesh, Ahmad, Dey, Aditya, Yang, Yufeng, Wang, Wuxiucheng, Chen, Shao, Wu, Hui, Askari, Hesam, Singh, Sobhit, Wu, Stephen M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 25.08.2023
• Subjects: Contact stresses; Controllability; Electric contacts; Electric fields; Electric potential; Film thickness; Memory devices; Memristors; Metal films; Multilayers; Performance measurement; Phase change; Phase transitions; Physics - Applied Physics; Physics - Mesoscale and Nanoscale Physics; Process parameters; Self alignment; Strain; Switching; Two dimensional materials; Voltage
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2308.13637

A new mechanism for memristive switching in 2D materials is through electric-field controllable electronic/structural phase transitions, but these devices have not outperformed status quo 2D memristors. Here, we report a high-performance bipolar phase change memristor from strain engineered multilayer 1T'-MoTe\(_{2}\) that now surpasses the performance metrics (on/off ratio, switching voltage, switching speed) of all 2D memristive devices, achieved without forming steps. Using process-induced strain engineering, we directly pattern stressed metallic contacts to induce a semimetallic to semiconducting phase transition in MoTe2 forming a self-aligned vertical transport memristor with semiconducting MoTe\(_{2}\) as the active region. These devices utilize strain to bring them closer to the phase transition boundary and achieve ultra-low ~90 mV switching voltage, ultra-high ~10\(^8\) on/off ratio, 5 ns switching, and retention of over 10\(^5\) s. Engineered tunability of the device switching voltage and on/off ratio is also achieved by varying the single process parameter of contact metal film force (film stress \(\times\) film thickness).