Two-dimensional gate dielectrics for field-effect transistors: from h-BN to emerging vdW and quasi-vdW materials

Recent progress in two-dimensional (2D) materials has generated immense interest in their use in field-effect transistors (FETs) for beyond-silicon electronics. Among them, 2D van der Waals (vdW) dielectrics play a pivotal role in facilitating high-performance, low-power devices, as they offer atomically smooth surfaces, no dangling bonds, and high electrostatic control. This review focuses on the latest developments in 2D vdW and quasi-vdW dielectrics, with emphasis on their electrical properties optimized for FETs. We highlighted the integration challenges of 3D dielectric materials for 2D semiconductors. Starting from hexagonal boron nitride (h-BN) and newly discovered dielectric materials such as rare-earth oxyhalides, transition metal oxyhalides, rare-earth oxysulfide, native oxide, muscovite mica, ferroelectric, alkaline-earth hydroxides, transition-metal nitride halides, quasi 2D dielectrics, and perovskite-based dielectrics are thoroughly discussed by highlighting their transistor performance. Device integration with these dielectrics has also been discussed. Finally, we discussed perspectives for future work to improve the 2D dielectric properties and scalability and realize compatibility with complementary metal–oxide–semiconductor (CMOS) technology.