Successfully Developed Technology of Making Wafer-scale MoS2-WS2 Vertical Heterostructures Using Low Temperature Plasma

- Joint research team composed of Prof. Tae-Sung Kim and Ji-Won Seok from the Department of Electrical Engineering at Sungkyunkwan University and Ph.D. Hyung-woo Kim from Korea Institute of Machinery & Materials
- Published in ACS Nano, an international academic journal online on January 7 (Thur)

[Image 1] From the left – Prof. Tae-Sung Kim, Ji-Won Seok and Ph.D Hyung-Woo

The joint research team (1^st author Hyun-Ho Seok, Yonas T. Megra, Chaitanya Kanade) was pleased to announce that they developed the technology of making 4 inches wafer-scale MoS2-WS2 vertical heterostructures for the first time.

The MoS2-WS2, representative transition metal dichalcogenides, are materials with different band gaps, and research for next-generation electronic device applications is being actively conducted. In particular, it is possible to adjust the band gap if the MoS2-WS2 are composed of vertical heterostructure, however, it has been difficult to manufacture a uniform heterostructure.

In response, the research team developed the technology to manufacture 4 inches of wafer-scale MoS2-WS2 vertical heterostructures via single step penetration sulfurization by PE-CVD at 300°C. It has developed a simple yet effective method of manufacturing heterostructure materials that use low-temperature plasma to sulfurize heterogeneous metal layers (molybdenum and tungsten) and applied the related technologies for a domestic patent. Moreover, the team analyzed the interfacial adhesion between large-scale heterostructure and the wafer through experiments with the concept of destructive mechanics and verified the structural stability of the MoS2-WS2 vertical heterostructures.

[Image 2] Illustration of the 2D transition material MoS2-WS2 and time-dependent conditions

Prof. Tae-Sung Kim said “It was the first time implementing the heterostructure between transition metal and it was implemented using synthesis method which has the advantage of low temperature process, high reproducibility, and uniformity. I expect that it will be able to accelerate progress and commercialization in research on heterostructures.”

This study was conducted with the support of National Research Foundation of Korea (NRF-2017R1A2B3011222, NRF-2019R1A2C2089785)와 and Korea Institute of Machinery & Materials. It was published in ACS Nano (IF: 14.588, JCR Top 10%), an international journal in the field of Material Science and Multidisciplinary online on January 7 (Thur).

※ Title: Low-Temperature Synthesis of Wafer-Scale MoS2-WS2 Vertical Heterostructures by Single-Step Penetrative Plasma Sulfurization