Reliable wafer-scale integration of two-dimensional materials and metal electrodes with van der Waals contacts

Abstract

Since the first report on single-layer MoS₂ based transistor, rapid progress has been achieved in two-dimensional (2D) material-based atomically thin electronics, providing an alternative approach to solve the bottleneck in silicon device miniaturization. In this scenario, reliable contact between the metal electrodes and the subnanometer-thick 2D materials becomes crucial in determining the device performance. Here, utilizing the quasi-van der Waals (vdW) epitaxy of metals on fluorophlogopite mica, we demonstrate an all-stacking method for the fabrication of 2D devices with high-quality vdW contacts by mechanically transferring pre-deposited metal electrodes. This technique is applicable for complex device integration with sizes up to the wafer scale and is also capable of tuning the electric characteristics of the interfacial junctions by transferring selective metals. Our results provide an efficient, scalable, and low-cost technique for 2D electronics, allowing high-density device integration as well as a handy tool for fundamental research in vdW materials.

2D semiconductors may offer a platform for future electronics, but the wafer-scale fabrication of high-performance 2D transistors remains challenging. Here, the authors report a universal all-stacking method to fabricate wafer-scale 2D electronic devices with van der Waals contacts, based on epitaxial metallic electrodes grown on fluorophlogopite mica.