Epitaxy of group-iii nitrides using metal-graphene encapsulation and ammonolysis
Innovative PVD method for epitaxial group-III nitride films on silicon using metal-graphene encapsulation to bypass traditional techniques, offering a cost-effective, scalable solution for high-quality film deposition.
Overview
The proposed technology introduces a novel physical vapor deposition (PVD) approach for creating epitaxial group-III nitride thin films on silicon substrates. By utilizing metal-graphene encapsulation and ammonolysis, this method circumvents traditional costly techniques such as MOCVD, MBE, and HVPE. The process involves depositing GaAlIn alloys, capping them with a nickel layer followed by amorphous carbon, which upon annealing, converts to multilayer graphene. This encapsulation prevents oxidation and facilitates a clean interface for nitridation, resulting in high-quality epitaxial films at lower costs.
Technical specifications
- Materials Used: Ga, Al, In, and GaAlIn alloys
- Process Steps:
- Thermal evaporation of metals on silicon substrates
- In situ capping with nickel/amorphous carbon
- Annealing to precipitate graphene
- Wet etching to remove nickel
- Ammonolysis for conversion to nitrides
- Characterization Techniques: Raman spectroscopy, reflectance, ellipsometry, AFM, TEM, XRD, Hall effect measurements, and PL mapping for film quality assessment.
- Scalability: Suitable for wafer-scale processing
Technology readiness level
This technology is currently at TRL 4, having proven its concept through laboratory validation. Further development will focus on optimizing film quality and scalability for commercial applications.
About UC Berkeley
UC Berkeley is a comprehensive public research university of global scale, known for cross‑disciplinary inquiry and a high‑intensity research culture. Industry engages on campus through shared user facilities, project‑based collaborations, and embedded innovation spaces, with proximity to a U.S. Department of Energy national laboratory enabling joint programs and access to specialized instrumentation. Its Bay Area location connects partners to deep talent pipelines and a dense startup ecosystem, enabling rapid prototyping and iteration alongside regional suppliers and investors. Research is supported by competitive federal funding from agencies such as the National Science Foundation, Department of Energy, National Institutes of Health, and DARPA. A dedicated technology transfer office streamlines IP, sponsored research, material transfer agreements, and startup formation, complemented by accelerators and proof‑of‑concept resources.
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