Indexed by: Journal paper

First Author: 林琪

Correspondence Author: 缪向水,徐明,TONG HAO

Co-author: Xingsheng Wang,Eshraghian,K.,Jason,yuanjunhui,冯金龙

Journal: Journal of Materials Chemistry C

Affiliation of Author(s): 华中科技大学

Discipline: Engineering

First-Level Discipline: Electronic Science And Technology

Document Type: J

Volume: 41

Issue: 9

Page Number: 14799-14807

DOI number: 10.1039/D1TC02150H

Date of Publication: 4445-12-01

Abstract: Conductive bridge threshold switching (CBTS) selector is a selector candidate for large-scale 3D crosspoint memory. In spite of its high selectivity, the generally low current density (JON) of <0.5 MA cm−2 is not practical for driving the memory elements. In particular, JON is the determining factor for the 3D PCM application owing to the greatly increased RESET current density in PCM cells as the size scales down. The low JON of CBTS selectors originates from the reduced number of conductive filament (CF) as the device scales down and the CF overgrowth induced long lifetime at a large current. Here, a strategy of inserting the super-ionic cation layer to form densely distributed Cu-rich cation sources is proposed to modulate the quantity and size of CFs. Multiple CFs grow from the cation sources to conduct current in parallel and CF overgrowth is prevented by local cation injection. The fabricated Pt/Cu2S/GeSe/Pt devices achieve a record 10 MA cm−2JON and 5 mA Idrive, realizing a ten-fold increase in the JON in CBTS selectors. Moreover, the selectivity is the highest at 1010, and the switching slope is <0.18 mV dec−1. The high-resolution transmission electron microscopy (HRTEM) image reveals multiple single-crystal nanochannels distributed in the Cu2S layer with a diameter of ∼20 nm and a distance of 15–20 nm, suggesting dense CF paths of small size. This method is practical for fabricating a scalable selector owing to the dense CF paths. The breakthrough in JON will greatly promote the practical use of CBTS selectors in 3D crosspoint memory.

Links to published journals: https://pubs.rsc.org/en/content/articlehtml/2021/tc/d1tc02150h