High resolution physical analysis of ohmic contact formation at GaN-HEMT devices. - Andreas Graff; Michél Simon-Najasek; Frank Altmann; Ján Kuzmík; Dagmar Gregusová; S. Hascik; Helmut Jung; T. Baur; Jan Grünenpütt; Hervé Blanck (Microelectron. Reliab., 2017)