Contact Engineering in Two-Dimensional Transition Metal Dichalcogenide-Based Devices: Industry-Compatible Approaches toward Ultralow Contact Resistance

The performance of electronic devices is critically governed by the contact properties at metal–semiconductor (MS) junctions, which directly affect the contact resistance (R_c) and charge transport characteristics. Accordingly, contact engineering has received considerable attention in the semiconductor industry. However, conventional contact engineering approaches designed for bulk semiconductors are not compatible with two-dimensional transition metal dichalcogenides (2D TMDCs) due to their atomically thin structure, thereby presenting challenges to the development of 2D electronic devices. In this Review, various alternative approaches are systematically explored to improve contact properties and reduce R_c at the metal–2D TMDC junction. We highlight recent progress in industry-compatible contact engineering techniques, especially those involving modifications of contact geometry. By establishing high-quality contact interfaces, these strategies are expected to play a crucial role in advancing the industrial application of next-generation 2D electronic devices in the post-silicon era.