Trench Etch Processing for SiC Superjunction Schottky Diodes

Abstract:

This study focuses on the trench etching process for the fabrication of SiC Superjunction Schottky diodes, utilizing an ICP-RIE technique. Through a series of experiments, we optimized the etching parameters, including ICP power, RF power, and SF₆ gas flow rates, to achieve etching rates ranging from 157 nm/min to 372.1 nm/min. Additionally, the study identified the performance of the hard mask as a critical issue during the etching process, which was improved by reducing the RF power below 80 w. The deepest trench achieved reached a depth of 21 μm at 75 w RF power, 1000 w ICP power and 40 sccm SF₆, confirming the feasibility of this approach for fabricating high-performance SiC superjunction devices.

• Periodical: Materials Science Forum (Volume 1159)
• Pages: 21-29
• DOI: https://doi.org/10.4028/p-kHnn3Q
• Online since: September 2025
• Authors: Qin Ze Cao*, Arne Benjamin Renz, Peter Michael Gammon, Neophytos Lophitis, Kyrylo Melnyk, Marina Antoniou
• Keywords: Device Fabrication, Inductively Coupled Plasma, Reactive Ion Etching, Schottky Diode, Silicon Carbide (SiC), Superjunction, Trench Devices

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