A mass transfer technology for high-density two-dimensional device integration

Abstract

The large-area transfer of two-dimensional (2D) materials from their growth substrate is crucial for electronic device integration. However, it is easy to damage sub-1-nm thick materials, and existing transfer methods typically involve a trade-off in terms of lateral size, quality and accuracy. Here we report a mass transfer printing technology that uses a polydimethylsiloxane stamp patterned with precisely arranged micro-posts to gently transfer wafer-level 2D arrays and to stack van der Waals heterostructure arrays. After the stamp is brought into contact with the 2D material, an ethanol–water solution is added, which penetrates the 2D material–growth substrate interface between the non-contact regions of the stamp and causes the film to delaminate. We use the approach to transfer a 2-inch (~5 cm) monolayer molybdenum disulfide film containing more than 1,000,000 arrays with lateral dimensions of 20 × 20 µm², a density of 62,500 arrays per cm² and a yield of 99% in a single operation. Integrated 2D transistors with different device architectures created with the technology show a device yield of around 97.9% (back gate) and nearly damage-free electrical properties (top and bottom gate). We also develop a capillary force-assisted transfer model to explain the rapid transfer mechanism.