Cross-sectional TEM and KOH-Etch Studies of Extended Defects in 3C-SiC p+n Junction Diodes Grown on 4H-SiC Mesas

This article presents cross-sectional transmission electron microscopy and molten-potassium hydroxide etching studies of (111) 3C-SiC diodes which we previously reported to be free of forward-voltage drift despite abundant electroluminescent linear features presumed to be defects. Our results show that the majority of linear features are stacking faults lying in inclined {111} planes. Additionally, high densities of isolated etch pits (106–108 cm−2) are observed in 3C films grown on stepped 4H mesas, while 3C films nucleated on step-free 4H mesas exhibited orders of magnitude fewer etch pits and stacking faults. Defect formation mechanisms whose impetuses are steps on the 4H-SiC pregrowth mesa are discussed.