Wafer‐Scale Amorphous g‐C 3 N 4 With Broadly Tunable Dielectric Properties for 2D Electronics

ABSTRACT Two‐dimensional (2D) semiconductors are regarded as promising candidates for next‐generation electronics due to their superior electrostatic control; however, their performance is severely constrained by the lack of suitable dielectric materials. Current dielectrics for 2D systems are predominantly limited to fixed high/low‐ κ materials, which cannot simultaneously satisfy the requirements of scaled transistors and low‐capacitance interconnects. Here, a facile chemical vapor deposition (CVD) strategy is demonstrated for the wafer‐scale and conformal growth of amorphous graphitic carbon nitride (g‐C 3 N 4 ) thin films on both planar and three‐dimensional (3D) substrates. By systematically modulating the growth parameters and substrate type, such as SiO 2 /Si, Al foil, and Cu foil, the dielectric constant of amorphous g‐C 3 N 4 is process‐based tuned over a broad range from 3.3 to 9.4. The resulting films exhibit excellent uniformity, good frequency and bias stability, and high breakdown fields of up to 10 MV cm −1 . Dual‐gate MoS 2 field‐effect transistors incorporating g‐C 3 N 4 as the top‐gate dielectric achieve an on/off current ratio exceeding 10 8 . This work establishes amorphous g‐C 3 N 4 as a versatile dielectric platform bridging low‐ κ and mid/high‐ κ regimes for 2D electronics and provides potentially generalizable guidelines for the design of related amorphous dielectrics in future 2D electronic devices.