Bubble-Free Transfer Technique for High-Quality Graphene/Hexagonal Boron Nitride van der Waals Heterostructures

Takuya Iwasaki, Kosuke Endo, Eiichiro Watanabe, Daiju Tsuya, Yoshifumi Morita, Shu Nakaharai, Yutaka Noguchi, Yutaka Wakayama, Kenji Watanabe, Takashi Taniguchi, Satoshi Moriyama

Research output: Contribution to journalArticle

Abstract

Bubbles at the interface of two-dimensional layered materials in van der Waals heterostructures cause deterioration in the quality of materials, thereby limiting the size and design of devices. In this paper, we report a simple all-dry transfer technique, with which the bubble formation can be avoided. As a key factor in the technique, a contact angle between a picked-up flake on a viscoelastic polymer stamp and another flake on a substrate was introduced by protrusion at the stamp surface. Using this technique, we demonstrated the fabrication of high-quality devices on the basis of graphene/hexagonal boron nitride heterostructures with a large bubble-free region. Additionally, the technique can be used to remove unnecessary flakes on a substrate under an optical microscopic scale. Most importantly, it improves the yield and throughput for the fabrication process of high-quality van der Waals heterostructure-based devices.

Original languageEnglish
JournalACS Applied Materials and Interfaces
DOIs
Publication statusAccepted/In press - 1 Jan 2020

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Keywords

  • 2D materials
  • all-dry transfer
  • bubble-free transfer technique
  • graphene/hexagonal boron nitride heterostructure
  • quantum Hall effect
  • van der Waals heterostructure

Cite this

Iwasaki, T., Endo, K., Watanabe, E., Tsuya, D., Morita, Y., Nakaharai, S., Noguchi, Y., Wakayama, Y., Watanabe, K., Taniguchi, T., & Moriyama, S. (Accepted/In press). Bubble-Free Transfer Technique for High-Quality Graphene/Hexagonal Boron Nitride van der Waals Heterostructures. ACS Applied Materials and Interfaces. https://doi.org/10.1021/acsami.9b19191