Reduced interface effect of proton beam irradiation on the electrical properties of WSe2/hBN field effect transistors

Seongmin Ko; Jiwon Shin; Juntae Jang; Jaeyong Woo; Jaeyoung Kim; Jaehyoung Park; Jongeun Yoo; Chongwu Zhou; Kyungjune Cho; Takhee Lee

doi:10.1088/1361-6528/ad403f

Reduced interface effect of proton beam irradiation on the electrical properties of WSe₂/hBN field effect transistors

Nanotechnology. 2024 May 7;35(30). doi: 10.1088/1361-6528/ad403f.

Authors

Affiliations

¹ Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea.
² Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA 90089, United States of America.
³ Convergence Research Center for Solutions to Electromagnetic Interference in Future-mobility, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.

PMID: 38636473
DOI: 10.1088/1361-6528/ad403f

Abstract

Two-dimensional transition metal dichalcogenide (TMDC) semiconductors are emerging as strong contenders for electronic devices that can be used in highly radioactive environments such as outer space where conventional silicon-based devices exhibit nonideal characteristics for such applications. To address the radiation-induced interface effects of TMDC-based electronic devices, we studied high-energy proton beam irradiation effects on the electrical properties of field-effect transistors (FETs) made with tungsten diselenide (WSe₂) channels and hexagonal boron-nitride (hBN)/SiO₂gate dielectrics. The electrical characteristics of WSe₂FETs were measured before and after the irradiation at various proton beam doses of 10¹³, 10¹⁴, and 10¹⁵cm^-2. In particular, we demonstrated the dependence of proton irradiation-induced effects on hBN layer thickness in WSe₂FETs. We observed that the hBN layer reduces the WSe₂/dielectric interface effect which would shift the transfer curve of the FET toward the positive direction of the gate voltage. Also, this interface effect was significantly suppressed when a thicker hBN layer was used. This phenomenon can be explained by the fact that the physical separation of the WSe₂channel and SiO₂dielectric by the hBN interlayer prevents the interface effects originating from the irradiation-induced positive trapped charges in SiO₂reaching the interface. This work will help improve our understanding of the interface effect of high-energy irradiation on TMDC-based nanoelectronic devices.

Keywords: 2D devices; WSe2; field effect transistor; interface effect; proton beam irradiation.