Non-invasive digital etching of van der Waals semiconductors.

Zhou, Jian; Zhang, Chunchen; Shi, Li; Chen, Xiaoqing; Kim, Tae Soo; Gyeon, Minseung; Chen, Jian; Wang, Jinlan et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

The capability to finely tailor material thickness with simultaneous atomic precision and non-invasivity would be useful for constructing quantum platforms and post-Moore microelectronics. However, it remains challenging to attain synchronized controls over tailoring selectivity and precision. Here we report a protocol that allows for non-invasive and atomically digital etching of van der Waals transition-metal dichalcogenides through selective alloying via low-temperature thermal diffusion and subsequent wet etching. The mechanism of selective alloying between sacrifice metal atoms and defective or pristine dichalcogenides is analyzed with high-resolution scanning transmission electron microscopy. Also, the non-invasive nature and atomic level precision of our etching technique are corroborated by consistent spectral, crystallographic, and electrical characterization measurements. The low-temperature charge mobility of as-etched MoS2 reaches up to 1200 cm2 V-1s-1, comparable to that of exfoliated pristine counterparts. The entire protocol represents a highly precise and non-invasive tailoring route for material manipulation.