Ultralow-Dielectric-Constant Atomic Layers of Amorphous Carbon Nitride Topologically Derived from MXene

Low-dielectric-constant materials such as silicon dioxide serving as interconnect insulators in current integrated circuit face a great challenge due to their relatively high dielectric constant of ≈4, twice that of the recommended value by the International Roadmap for Devices and Systems, causing severe parasitic capacitance and associated response delay. Here, novel atomic layers of amorphous carbon nitride (a-CN) are prepared via a topological conversion of MXene-Ti₃ CNT_x under bromine vapor. Remarkably, the assembled a-CN film exhibits an ultralow dielectric constant of 1.69 at 100 kHz, much lower than the previously reported dielectric materials such as amorphous carbon (2.2) and fluorinated-doped SiO₂ (3.6), ascribed to the low density of 0.55 g cm^-3 and high sp³ C level of 35.7%. Moreover, the a-CN film has a breakdown strength of 5.6 MV cm^-1 , showing great potential in integrated circuit application.