Thin Fluoride Insulators for Improved 2D Transistors: From Deposition Methods to Recent Applications

2D materials are highly promising for next‐generation electronic and optoelectronic devices. The integration of 2D materials as channel layers in field effect transistors (FETs) could enable their aggressive downscaling, beyond the limits that are currently affecting Si‐based devices. However, the realization of high‐performance 2D‐based devices is hindered by challenges in identifying suitable gate dielectrics. Conventional high‐k dielectrics often introduce interface defects that can degrade the electrical transport properties. Recently, crystalline ionic insulators such as CaF 2 and other fluorides have emerged as promising alternatives due to their inert, dangling‐bond‐free surfaces. Herein, different publications are discussed that describe some of the experimental techniques that can be employed for the deposition of high‐quality fluoride thin films, such as molecular beam epitaxy, thermal evaporation, and magnetron sputtering, with a focus on the strategies for obtaining smooth surfaces, good stoichiometry, and high packing density. Finally, some of the most recent publications that describe the integration of these dielectrics into 2D‐FETs are presented, highlighting their impact on the electrical transport, underscoring their potential for enabling scalable fabrication of high‐performance 2D electronic devices.