High-Fidelity Transfer of 2D Semiconductors and Electrodes for van der Waals Devices
Lingxiao Yu, Minglang Gao, Qian Lv, Hanyuan Ma, Jingzhi Shang, Zheng‐Hong Huang, Zheng Sun, Ting Yu, Feiyu Kang, Ruitao Lv
Abstract
As traditional silicon-based materials almost reach their limits in the post-Moore era, two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been regarded as next-generation semiconductors for high-performance electrical and optical devices. Chemical vapor deposition (CVD) is a widely used technique for preparing large-area and high-quality TMDCs. Yet, it suffers from the challenge of transfer due to the strong interaction between 2D materials and substrates. The traditional PMMA-assisted wet etching method tends to induce damage, wrinkles, and inevitable polymer residues. In this work, we propose an etch-free and clean transfer method via a water intercalation strategy for TMDCs, ensuring a high-fidelity, wrinkle-free, and crack-free transfer with negligible residues. Furthermore, metal electrodes can also be transferred via this method and back-gate field-effect transistors (FETs) based on CVD-grown monolayer WSe 2 with van der Waals (vdW) metal/semiconductor contacts are fabricated. Compared to the PMMA-assisted transfer method (∼1.2 cm 2 V –1 s –1 hole mobility with ∼2 × 10 6 ON/OFF ratio), our high-fidelity transfer method significantly enhances the electrical performance of WSe 2 FET over one order of magnitude, achieving a hole mobility of ∼43 cm 2 V –1 s –1 and a high ON/OFF ratio of ∼5 × 10 7 in air at room temperature.