*Article* **Mechanisms of Ohmic Contact Formation of Ti/Al-Based Metal Stacks on p-Doped 4H-SiC**

**Matthias Kocher 1,\*, Mathias Rommel <sup>1</sup> , Pawel Michalowski <sup>2</sup> and Tobias Erlbacher 1,3**


**Abstract:** Ohmic contacts on p-doped 4H-SiC are essential for the fabrication of a wide range of power electron devices. Despite the fact that Ti/Al based ohmic contacts are routinely used for ohmic contacts on p-doped 4H-SiC, the underlying contact formation mechanisms are still not fully understood. TLM structures were fabricated, measured and analyzed to get a better understanding of the formation mechanism. SIMS analyses at the Ti3SiC<sup>2</sup> -SiC interface have shown a significant increase of the surface near Al concentration. By using numerical simulation it is shown that this additional surface near Al concentration is essential for the ohmic contact formation.

**Keywords:** 4H-SiC; ohmic contact; SIMS; Ti3SiC<sup>2</sup> ; simulation

**Citation:** Kocher, M.; Rommel, M.; Michalowski, P.; Erlbacher, T. Mechanisms of Ohmic Contact Formation of Ti/Al-Based Metal Stacks on p-Doped 4H-SiC. *Materials* **2022**, *15*, 50. https://doi.org/ 10.3390/ma15010050

Academic Editor: Fabrizio Roccaforte

Received: 22 October 2021 Accepted: 16 December 2021 Published: 22 December 2021

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