Resistance Switching Characteristics Induced by O2 Plasma Treatment of an Indium Tin Oxide Film for Use as an Insulator in Resistive Random Access Memory

Po-Hsun Chen; Ting-Chang Chang; Kuan-Chang Chang; Tsung-Ming Tsai; Chih-Hung Pan; Min-Chen Chen; Yu-Ting Su; Chih-Yang Lin; Yi-Ting Tseng; Hui-Chun Huang; Huaqiang Wu; Ning Deng; He Qian; Simon M Sze

doi:10.1021/acsami.6b14282

Resistance Switching Characteristics Induced by O₂ Plasma Treatment of an Indium Tin Oxide Film for Use as an Insulator in Resistive Random Access Memory

ACS Appl Mater Interfaces. 2017 Jan 25;9(3):3149-3155. doi: 10.1021/acsami.6b14282. Epub 2017 Jan 10.

Authors

Po-Hsun Chen¹, Ting-Chang Chang^{1

2}, Kuan-Chang Chang^{3

4}, Tsung-Ming Tsai³, Chih-Hung Pan³, Min-Chen Chen¹, Yu-Ting Su¹, Chih-Yang Lin¹, Yi-Ting Tseng¹, Hui-Chun Huang³, Huaqiang Wu⁴, Ning Deng⁴, He Qian⁴, Simon M Sze⁵

Affiliations

¹ Department of Physics, National Sun Yat-Sen University , Kaohsiung 804, Taiwan R. O. C.
² Advanced Optoelectronics Technology Center, National Cheng Kung University , Tainan 701, Taiwan R. O. C.
³ Department of Materials and Optoelectronic Science, National Sun Yat-Sen University , Kaohsiung 804, Taiwan R. O. C.
⁴ Institute of Microelectronics, Tsinghua University , Beijing 100084, China.
⁵ Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University , Hsinchu 300, Taiwan R. O. C.

PMID: 28072511
DOI: 10.1021/acsami.6b14282

Abstract

In this study, an O₂ inductively coupled plasma (ICP) treatment was developed in order to modify the characteristics of indium tin oxide (ITO) film for use as an insulator in resistive random access memory (RRAM). After the O₂ plasma treatment, the previously conductive ITO film is oxidized and becomes less conductive. In addition, after capping the same ITO material for use as a top electrode, we found that the ITO/ITO(O₂ plasma)/TiN device exhibits very stable and robust resistive switching characteristics. On the contrary, the nontreated ITO film for use as an insulator in the ITO/ITO/TiN device cannot perform resistance switching behaviors. The material analysis initially investigated the ITO film characteristics with and without O₂ plasma treatment. The surface was less rough after O₂ plasma treatment. However, the molar concentration of each element and measured sheet resistance results for the O₂-plasma-treated ITO film were dramatically modified. Next, electrical measurements were carried out to examine the resistance switching stability under continuous DC and AC operation in this ITO/ITO(O₂ plasma)/TiN device. Reliability tests, including endurance and retention, also proved its capability for use in data storage applications. In addition to these electrical measurements, current fitting method experiments at different temperatures were performed to examine and confirm the resistance switching mechanisms. This easily fabricated device, using a simple material combination, achieves excellent performance by using ITO with an O₂ plasma treatment and can further the abilities of RRAM for use in remarkable potential applications.

Keywords: indium tin oxide (ITO); inductively coupled plasma (ICP); insulator; oxygen gas (O2); resistive random access memory (RRAM); self-compliance current.