Phase/Interfacial-Engineered Two-Dimensional-Layered WSe2 Films by a Plasma-Assisted Selenization Process: Modulation of Oxygen Vacancies in Resistive Random-Access Memory

Mayur Chaudhary, Yu Chuan Shih, Shin Yi Tang, Tzu Yi Yang, Tzu Wen Kuo, Chia Chen Chung, Ying Chun Shen, Aswin kumar Anbalagan, Chih Hao Lee, Tuo Hung Hou, Jr Hau He*, Yu Lun Chueh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Here, we propose phase and interfacial engineering by inserting a functional WO3 layer and selenized it to achieve a 2D-layered WSe2/WO3 heterolayer structure by a plasma-assisted selenization process. The 2D-layered WSe2/WO3 heterolayer was coupled with an Al2O3 film as a resistive switching (RS) layer to form a hybrid structure, with which Pt and W films were used as the top and bottom electrodes, respectively. The device with good uniformity in SET/RESET voltage and high low-/high-resistance window can be obtained by controlling a conversion ratio from a WO3 film to a 2D-layered WSe2 thin film. The Pt/Al2O3/(2D-layered WSe2/WO3)/W structure shows remarkable improvement to the pristine Pt/Al2O3/W and Pt/Al2O3/2D-layered WO3/W in terms of low SET/RESET voltage variability (−20/20)%, multilevel characteristics (uniform LRS/HRS distribution), high on/off ratio (104-105), and retention (∼105 s). The thickness of the obtained WSe2 was tuned at different gas ratios to optimize different 2D-layered WSe2/WO3 (%) ratios, showing a distinctive trend of reduced and uniform SET/RESET voltage variability as 2D-layered WSe2/WO3 (%) changes from 90/10 (%) to 45/55 (%), respectively. The electrical measurements confirm the superior ability of the metallic 1T phase of the 2D-layered WSe2 over the semiconducting 2H phase. Through systemic studies of RS behaviors on the effect of 1T/2H phases and 2D-layered WSe2/WO3 ratios, the low-temperature plasma-assisted selenization offers compatibility with the temperature-limited 3D integration process and also provides much better thickness control over a large area.

Original languageEnglish
Pages (from-to)33858-33867
Number of pages10
JournalACS Applied Materials and Interfaces
Volume15
Issue number28
DOIs
StatePublished - 19 Jul 2023

Keywords

  • 2D layered-WSe/WO
  • conducting filament
  • interfacial engineering
  • plasma-assisted chemical vapor reaction
  • the functional layer

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