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 WSe₂ with van der Waals (vdW) metal/semiconductor contacts are fabricated. Compared to the PMMA-assisted transfer method (∼1.2 cm² V^–1 s^–1 hole mobility with ∼2 × 10⁶ ON/OFF ratio), our high-fidelity transfer method significantly enhances the electrical performance of WSe₂ FET over one order of magnitude, achieving a hole mobility of ∼43 cm² V^–1 s^–1 and a high ON/OFF ratio of ∼5 × 10⁷ in air at room temperature.

中文翻译：

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用于范德华器件的 2D 半导体和电极的高保真转移


随着传统硅基材料在后摩尔时代几乎达到极限，二维 （2D） 过渡金属硫化物 （TMDC） 被视为高性能电气和光学器件的下一代半导体。化学气相沉积 （CVD） 是一种广泛用于制备大面积和高质量 TMDC 的技术。然而，由于 2D 材料和基板之间的强烈相互作用，它面临着转移的挑战。传统的 PMMA 辅助湿法蚀刻方法往往会引起损伤、皱纹和不可避免的聚合物残留物。在这项工作中，我们提出了一种通过水嵌入策略对 TMDC 进行无蚀刻和清洁的转移方法，确保高保真、无皱纹和无裂纹的转移，残留物可以忽略不计。此外，金属电极也可以通过这种方法转移，并制造了基于 CVD 生长单层 WSe₂ 和范德华 （vdW） 金属/半导体触点的背栅场效应晶体管 （FET）。与 PMMA 辅助转移方法（∼1.2 cm² V^–1 s^–1 空穴迁移率，∼2^{× 10 6} 开/关比）相比，我们的高保真转移方法在一个数量级上显著提高了 WSe₂ FET 的电气性能，在室温下实现了 ∼43 cm² V^–1 s^–1 的空穴迁移率和 ∼5 × 10⁷ 的高开/关比。