DIASEMI nanocrystalline low-k CVD diamond membranes
DIASEMI nanocrystalline low-k CVD diamond membranes
At DIASEMI, advanced nanocrystalline diamond (NCD) films with engineered surface morphology and ultra-low dielectric properties are developed using a proprietary bias-assisted hot filament chemical vapor deposition (HFCVD) process. By precisely controlling CH₄ concentration and substrate bias during deposition, DIASEMI successfully tailors the microstructure, grain size, and porosity of the diamond membrane to achieve next-generation low-k performance for high-frequency electronic applications.
Our studies demonstrate that the dielectric constant of nanocrystalline diamond films decreases significantly with increasing methane concentration during growth. Under optimized deposition conditions of 16% CH₄ concentration and a substrate bias of −200 V, DIASEMI achieved a low-k nanocrystalline diamond membrane featuring:
• Average grain size: ~10–20 nm
• Dielectric constant (k): as low as 2.4
• Ultra-low dielectric loss tangent (~10⁻⁴)
• Excellent thermal and chemical stability
The ultra-low dielectric constant originates from two synergistic structural mechanisms:
Nanocrystal Grain Refinement
The reduction of diamond grain size into the nanometer regime induces a band-gap expansion effect, lowering electronic polarizability and thereby reducing the dielectric constant.Nanoporous Low-k Architecture
Elevated CH₄ concentration promotes the formation of controlled nanoporous structures within the nanocrystalline diamond membrane. Since air-filled nanopores possess an extremely low dielectric constant (k ≈ 1), the effective dielectric constant of the film is further reduced according to the two-phase dielectric mixing model.
Combining ultra-low dielectric constant with the intrinsic advantages of CVD diamond, DIASEMI nanocrystalline low-k diamond membranes provide:
• Excellent thermal conductivity
• High electrical insulation and breakdown strength
• Superior chemical and radiation stability
• Outstanding thermal reliability
• Wide operating temperature capability
These advanced low-k diamond materials are highly promising for:
• Ultra-large-scale integrated circuits (ULSI)
• High-speed interconnect dielectrics
• RF, microwave, and millimeter-wave devices
• 5G/6G communication modules
• Advanced semiconductor packaging
• High-speed electronic substrates
• Photonic and optoelectronic integration
DIASEMI nanocrystalline low-k CVD diamond membranes represent a next-generation platform material for high-speed, high-frequency, and high-power electronic systems.
