Fast direct write laser lithography for large area van der Waals devices

Abstract Exfoliated flakes of van der Waals (vdW) materials and vdW heterostructures host exotic electronic phases that are interesting for fundamental physics and future applications. Electron beam lithography is the major step involved in fabricating devices using vdW flakes and is an expensive and time-consuming step that can prevent quick prototyping. Here we introduce a fast direct write lithography technique to fabricate vdW devices using an ultraviolet (UV) laser source (325 nm) and an automated XY stage, both typically accessible to experimentalists working on vdW flakes. We provide an optimized recipe (achieving a minimum linewidth of 2 µ m) along with demonstrative experiments measuring Shubnikov de Haas oscillations and recently discovered Sondheimer oscillations on a thin graphite flake at low temperatures. With a growing interest in devices using few-layer and large-area vdW flakes, we believe that this easy-to-implement technique will be highly beneficial for the vdW research community. Coupled with a flake identification system, this technique can enable automated device fabrication and significantly improve the yield of devices using exfoliated flakes.