Near-zero-adhesion-enabled intact wafer-scale resist-transfer printing for high-fidelity nanofabrication on arbitrary substrates

Key words: 
• resist-based transfer printing /
• near-zero adhesion /
• critical surface energy /
• wafer-scale nanofabrication /
• in situ fabrication /
• optoelectronic devices

Abstract: 

There is an urgent need for novel processes that can integrate different functional nanostructures onto specific substrates, so as to meet the fast-growing need for broad applications in nanoelectronics, nanophotonics, and flexible optoelectronics. Existing direct-lithography methods are difficult to use on flexible, nonplanar, and biocompatible surfaces. Therefore, this fabrication is usually accomplished by nanotransfer printing. However, large-scale integration of multiscale nanostructures with unconventional substrates remains challenging because fabrication yields and quality are often limited by the resolution, uniformity, adhesivity, and integrity of the nanostructures formed by direct transfer. Here, we proposed a resist-based transfer strategy enabled by near-zero adhesion, which was achieved by molecular modification to attain a critical surface energy interval. This approach enabled the intact transfer of wafer-scale, ultrathin-resist nanofilms onto arbitrary substrates with mitigated cracking and wrinkling, thereby facilitating the in situ fabrication of nanostructures for functional devices. Applying this approach, fabrication of three-dimensional-stacked multilayer structures with enhanced functionalities, nanoplasmonic structures with ~10 nm resolution, and MoS₂-based devices with excellent performance was demonstrated on specific substrates. These results collectively demonstrated the high stability, reliability, and throughput of our strategy for optical and electronic device applications.