Characterization of Co-Sputtered Amorphous SiTe Thin Films for Ovonic Threshold Switch Device

Jeongun Choe1,2, Deok-Jin Jeon1,2, Jihye Lee1,2, and Jong-Souk Yeo1,2

1School of Integrated Technology, Yonsei University, Incheon, Republic of Korea

2Yonsei Institute of Convergence Technology, Yonsei University, Incheon, Republic of Korea

E-mail: jongsoukyeo@yonsei.ac.kr

Recently, as research on big data or artificial intelligence has been actively conducted, new memory device design such as neuromorphic device architecture or synaptic device architecture has become increasingly important. According to this trend, there is a growing demand for ultracompact non-volatile memory devices that are integrated with switch devices. To drive the highly-integrated memory cell properly, selector devices are actively investigated to meet several conditions. For example, low sneak current, high on/off ratio, scalability, and bidirectional driving characteristics must be satisfied. A strong candidate material for the selector device is amorphous chalcogenide to integrate with a phase change non-volatile memory. Especially, SiTe, a binary compound chalcogenide, has been actively investigated because of its good ovonic threshold switching (OTS) characteristics. In this study, SiTe thin films deposited by co-sputtering technology are analyzed to obtain better ovonic threshold switching characteristics by changing sputtering conditions. Crystallographic analysis is carried out using x-ray diffraction (XRD) analysis to confirm the amorphous SiTe thin film and x-ray photoelectron spectroscopy (XPS) analysis is performed to confirm the compositional ratio. The OTS device is fabricated by using the SiTe thin film and the electrical properties of the device are further characterized.

This research was supported by the MOTIE (Ministry of Trade, Industry & Energy (project number 10080625) and KSRC (Korea Semiconductor Research Consortium) support program for the development of the future semiconductor device.

Keyword: SiTe, Chalcogenide, Ovonic threshold switch, Neuromorphic device, XRD