Low-Ohmic Nickel Contacts on N-Type 4H-SiC by Surface Roughness Dependent Laser Annealing Energy Density Optimization

Abstract:

In this work, the influence of different surface roughness and surface treatments on the minimum energy density required to form low-ohmic nickel contacts on n-type 4H-SiC by laser annealing was investigated. The annealing was performed by a frequency-tripled Nd:YVO₄ laser with a pulse duration of 50 ns. To evaluate the effects, the grinded or polished C-side of 4H-SiC wafers with surface roughness between 0.3 and 70 nm was sputter-deposited with nickel and subsequent laser annealed. Sheet resistance measurements showed that the minimum energy density required to achieve a low-resistance contact depends significantly on the surface roughness. The rougher the surface, the lower the minimum energy density to form a low-ohmic contact.

• Periodical: Solid State Phenomena (Volume 359)
• Pages: 113-118
• DOI: https://doi.org/10.4028/p-Fm2zFp
• Online since: August 2024
• Authors: Carsten Hellinger*, Mathias Rommel, Anton J. Bauer
• Keywords: Grinding, Laser Annealing, Nickel, Ohmic Contact

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