Transferrable Alumina Membranes as High-Performance Dielectric for Flexible 2D Materials Devices

2D materials have shown great promise for novel electronic functionality. A common challenge for 2D materials-based transistors is forming a high-performance gate terminal due to the challenges of depositing a dielectric of sufficient quality and controllable thickness. Herein the van-der-Waals integration of a free-standing Al2O3 dielectric membrane is demonstrated as a facile, scalable, and powerful gate dielectric. A process is developed that permits the wet transfer of an amorphous alumina layer with a finely adjustable equivalent oxide thickness (EOT) in the single nanometer range. Electrical characterization demonstrates the high breakdown field and low leakage of the dielectric and integration into 2D materials transistors reveals a high performance. The wafer-scale uniformity of the dielectric membrane permits the formation of large-scale flexible devices that exhibit good robustness and long-term stability. The integration of next-generation dielectrics is a critical requirement for improving electronic devices. Here a facile approach is presented to create free-standing dielectric membranes that can simply be transferred onto transistor channels. The van-der-Waals integrated gate exhibits good leakage properties while retaining the high quality of the channel and achieving mechanical flexibility. image