Iwasaki Takuya, Endo Kosuke, Watanabe Eiichiro, Tsuya Daiju, Morita Yoshifumi, Nakaharai Shu, Noguchi Yutaka, Wakayama Yutaka, Watanabe Kenji, Taniguchi Takashi, Moriyama Satoshi
International Center for Young Scientists (ICYS) , National Institute for Materials Science (NIMS) , Tsukuba , Ibaraki 305-0044 , Japan.
International Center for Materials Nanoarchitectonics (WPI-MANA), NIMS , Tsukuba , Ibaraki 305-0044 , Japan.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8533-8538. doi: 10.1021/acsami.9b19191. Epub 2020 Feb 6.
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.
范德华异质结构中二维层状材料界面处的气泡会导致材料质量下降，从而限制器件的尺寸和设计。在本文中，我们报告了一种简单的全干法转移技术，利用该技术可以避免气泡形成。作为该技术的一个关键因素，通过粘弹性聚合物印章表面的凸起引入了拾取薄片与衬底上另一片薄片之间的接触角。利用该技术，我们展示了基于石墨烯/六方氮化硼异质结构且具有大无气泡区域的高质量器件的制造。此外，该技术可用于在光学显微镜尺度下去除衬底上不必要的薄片。最重要的是，它提高了基于高质量范德华异质结构的器件制造过程的产量和吞吐量。
