MA: Ni-Si and Multilayer Metallization Schemes for Rapid Thermal Annealed Ohmic Contacts to 4H-SiC

17. Dezember 2025

Lutz Hager –

This thesis focuses on adapting and optimizing a novel fabrication process for ohmic contacts on 4H-Silicon Carbide (4H-SiC) devices, leveraging the advanced manufacturing capabilities at the Fraunhofer Institute and the Chair of Electron Devices. The primary objective is to optimize the established Ni-based n-type contacts by introducing Silicon interlayers. This method addresses the formation of carbon-rich segregation layers – a known failure mechanism in conventional NiSi contacts – by promoting the formation of nickel silicides predominately by the added Si and Ni layers, thereby preserving the SiC substrate’s integrity.
Complementing this optimization, the work includes a comparative study of alternative material stacks to evaluate their viability as stable ohmic contacts.
The contacts will be formed using Rapid Thermal Annealing (RTA) and characterized using electrical 4-point probe measurements and the Circular Transfer Length Method (cTLM).

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