High-Quality Exfoliation and Integration of Large-Area Transition Metal Dichalcogenide Monolayers with Wafer Bonder

Transition metal dichalcogenides (TMDCs) monolayers and their heterostructures have attracted tremendous research interests in the past decades, for their remarkable physical properties. However, producing such two-dimensional (2D) monolayers with both desired lateral scale and film quality still needs effort. Here, we report a nifty and generic way to achieve high quality large-area TMDC monolayers and their assembly from bulk crystals, with improved control over cracks and strain based on the Au-assist exfoliation technique. Wafer bonder is used during the process for: 1) applying controllable and uniform force to integrate monolayers onto desired substrates, 2) supporting a high vacuum (HV) environment to eliminate air bubbles between layers, and 3) maintaining the desired temperature. Both optical and electrical characterizations of different TMDC monolayers confirm the high quality over a centimeter scale. This high-throughput method could be beneficial to the fundamental physical studies as well as the electronic and photonic applications of the TMDC materials.