Indexed by: Journal paper

First Author: WANG LUN

Correspondence Author: TONG HAO

Co-author: 缪向水,陈江西,朱荣江,温晋宇

Journal: Applied Physics Letters

Affiliation of Author(s): 华中科技大学

Discipline: Engineering

First-Level Discipline: Electronic Science And Technology

Document Type: J

Volume: 121

Issue: 19

Page Number: 193501

Key Words: Ab-initio molecular dynamics, Density functional theory, Exchange correlation functionals, First-principle calculations, Electrical properties and parameters, Current-voltage characteristic, Materials properties, Separation processes, Phase change memories

DOI number: 10.1063/5.0127177

Date of Publication: 4487-02-01

Abstract: The endurance of ovonic threshold switching (OTS) selectors is a key element for memory application. However, multi-element system for OTS in recent studies will induce element or phase segregation and lead to device failure. Since pure Te based device characterizes relatively high off current, in this work, we studied a Te-rich Ge–Te based OTS selector. We first conducted a failure analysis on Ge–Te based OTS selector. Through first-principles calculations, we found that a relatively larger Ge concentration in the Ge–Te system may lead to a worse device endurance after continuous operation due to the migration of Ge atoms. Experiments further proved that device endurance can be improved more than two orders of magnitude through decreasing Ge concentration and the element segregation is greatly weakened by the composition close to elemental. Finally, a significantly improved endurance of 2  1010 was realized in Ge10Te90 based OTS selectors. In the meantime, the Ge10Te90 based OTS selectors show good switching performance and potential for use in memory applications.

Links to published journals: https://pubs.aip.org/aip/apl/article/121/19/193501/2834756/Failure-mechanism-investigation-and-endurance