Liquid Metal Oxide-Assisted Integration of High-k Dielectrics and Metal Contacts for Two-Dimensional Electronics
Dasari Venkatakrishnarao, Abhishek Mishra, Yaoju Tarn, Michel Bosman, Rainer Lee, Sarthak Das, Subhrajit Mukherjee, Teymour Talha-Dean, Yiyu Zhang, Siew Lang Teo, Jianwei Chai, Fabio Bussolotti, Kuan Eng Johnson Goh, Chit Siong Lau
Abstract
Two-dimensional van der Waals semiconductors are promising for future nanoelectronics. However, integrating high-k gate dielectrics for device applications is challenging as the inert van der Waals material surfaces hinder uniform dielectric growth. Here, we report a liquid metal oxide-assisted approach to integrate ultrathin, high-k HfO 2 dielectric on 2D semiconductors with atomically smooth interfaces. Using this approach, we fabricated 2D WS 2 top-gated transistors with subthreshold swings down to 74.5 mV/dec, gate leakage current density below 10 –6 A/cm 2, and negligible hysteresis. We further demonstrate a one-step van der Waals integration of contacts and dielectrics on graphene. This can offer a scalable approach toward integrating entire prefabricated device stack arrays with 2D materials. Our work provides a scalable solution to address the crucial dielectric engineering challenge for 2D semiconductor-based electronics.