Insulating SiO<sub>2</sub> under Centimeter-Scale, Single-Crystal Graphene Enables Electronic-Device Fabrication.

Guo, Hui; Wang, Xueyan; Huang, Li; Jin, Xin; Yang, Zhenzhong; Zhou, Zhang; Hu, Hai; Zhang, Yu-Yang et al. · Nano Lett · 2020

basic_science · Level V

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Abstract

Graphene on SiO<sub>2</sub> enables fabrication of Si-technology-compatible devices, but a transfer of these devices from other substrates and direct growth have severe limitations due to a relatively small grain size or device-contamination. Here, we show an efficient, transfer-free way to integrate centimeter-scale, single-crystal graphene, of a quality suitable for electronic devices, on an insulating SiO<sub>2</sub> film. Starting with single-crystal graphene grown epitaxially on Ru(0001), a SiO<sub>2</sub> film is grown under the graphene by stepwise intercalation of silicon and oxygen. Thin (∼1 nm) crystalline or thicker (∼2 nm) amorphous SiO<sub>2</sub> has been produced. The insulating nature of the thick amorphous SiO<sub>2</sub> is verified by transport measurements. The device-quality of the corresponding graphene was confirmed by the observation of Shubnikov-de Haas oscillations, an integer quantum Hall effect, and a weak antilocalization effect within <i>in situ</i> fabricated Hall bar devices. This work provides a reliable platform for applications of large-scale, high-quality graphene in electronics.