Nitrogen-doped amorphous carbon as atomically thin monolithic membrane

Abstract

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  Remote plasma growth of large-area, uniform, and pinhole-free NDAC films
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  Thickness tunable from sub-1 nm to several nm with atomic-scale roughness
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  Peening-driven downhill transport mechanism is revealed
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  Sub-1 nm NDAC enables superior property as Cu diffusion barriers

Two-dimensional amorphous materials offer compelling advantages including atomic-scale thickness, tunable properties, and high defect tolerance. Significant progress has been made in synthesizing such materials, ranging from monolayer amorphous carbon to ultrathin oxides and nitrides. These efforts have begun to establish a coherent research framework linking synthesis, structural characterization, and property exploration. Unlike two-dimensional crystalline materials, amorphous thin films are free from grain boundaries and van der Waals gaps, enabling truly monolithic membranes with atomic-scale smoothness. Further advances are expected by developing scalable and low-temperature deposition methods, engineering local bonding configurations (e.g., sp/sp ratio and doping), and integrating these membranes into functional devices. With continued theoretical and experimental efforts, atomically thin amorphous materials have the potential to serve as versatile building blocks for next-generation electronics, selective barriers, and ultrathin optical components, opening new avenues beyond the paradigm of layered crystals.

Atomically thin amorphous materials represent a burgeoning class of materials that combine modulations in dimensionality and crystallinity, thereby bypassing crystalline lattice-symmetry constraints. Vitreous materials beyond the monolayer limit, in principle, provide unprecedented ultrathin and monolithic frameworks with structural uniformity but are mostly uncharted territories. Here, we report the remote plasma-assisted growth of nitrogen-doped amorphous carbon (NDAC) membranes, achieving atomic-scale roughness and tunable thicknesses ranging from sub-1 nm to several nanometers. Simulation results suggest that a peening-driven downhill transport mechanism governs this growth process. Electron microscopy confirms that NDAC membranes are pinhole free and structurally robust, characterized by a hybrid sp²/sp³ carbon bonding network. We evaluated the electron transmittance of the self-supported NDAC thin films and demonstrated the versatility of NDAC as back-end-of-line-compatible, sub-1-nm Cu diffusion barriers directly deposited on dielectrics. These results underscore the unique structural advantages of atomically thin amorphous solids, establishing them as critical components for next-generation advanced electronics.

Atomically thin amorphous materials represent a burgeoning class of materials that combine modulations in dimensionality and crystallinity, thereby bypassing crystalline lattice-symmetry constraints. Vitreous materials beyond the monolayer limit, in principle, provide unprecedented ultrathin and monolithic frameworks with structural uniformity but are mostly uncharted territories. Here, we report the remote plasma-assisted growth of nitrogen-doped amorphous carbon (NDAC) membranes, achieving atomic-scale roughness and tunable thicknesses ranging from sub-1 nm to several nanometers. Simulation results suggest that a peening-driven downhill transport mechanism governs this growth process. Electron microscopy confirms that NDAC membranes are pinhole free and structurally robust, characterized by a hybrid sp²/sp³ carbon bonding network. We evaluated the electron transmittance of the self-supported NDAC thin films and demonstrated the versatility of NDAC as back-end-of-line-compatible, sub-1-nm Cu diffusion barriers directly deposited on dielectrics. These results underscore the unique structural advantages of atomically thin amorphous solids, establishing them as critical components for next-generation advanced electronics.

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