Current collapse suppression in AlGaN/GaN HEMTs by means of slant field plates fabricated by multi-layer SiCN

•We report a new fabrication process to realize a slant field plate using a multi-layer SiCN film.•AlGaN/GaN HEMTs with several shapes of conventional and slant field plates are fabricated.•The current collapse of HEMTs with several shapes of field plates is compared experimentally.•The slant field plates suppress the current collapse more than the conventional field plates.