SIMS Analyses Applied to Open an Optical Window in 4H-SiC Devices for Electro-Optical Measurements

Abstract

4H-SiC vertical bipolar power diodes have been fabricated with bilayer metallic anode contact based on an Al-Ti-Ni ohmic contact and a thick Al over-metallization. An optical window of 100 × 100 μm2 has been created through the anode contact with a SIMS Cameca IMS 4F equipment using Cs+ primary ions at 10 kV and with a beam spot size of 100 nm. The current/voltage characteristics of the diodes show that the SIMS process does not induce an increase of the leakage currents in forward nor in reverse bias. OBIC UV photogeneration occurs under the optical window and not under the contact metal.