Reliability issues of gate oxides and $p-n$ junctions for vertical GaN metal-oxide-semiconductor field-effect transistors (Invited). - Tetsuo Narita; Daigo Kikuta; Kenji Ito; Tomoyuki Shoji; Tomohiko Mori; Satoshi Yamaguchi; Yasuji Kimoto; Kazuyoshi Tomita; Masakazu Kanechika; Takeshi Kondo; Tsutomu Uesugi; Jun Kojima; et al. (IRPS, 2023)