Figure 4
From: Polarity-inverted lateral overgrowth and selective wet-etching and regrowth (PILOSWER) of GaN
(a) A cross-sectional SEI of regrown GaN obtained by scanning transmission electron microscopy. An inset is a color-coded schematic diagram of the cross-sectional view. The regions in blue, green, violet represent GaN, SiO2, and sapphire. A dashed white line marks a crack caused during sample preparation. (b) A magnified image of the region marked by a white rectangle in (a). (c) An EDX line profile measured along a 40-nm-long white line marked in (b). A 4∼5-nm-thick layer on top of a sapphire surface consists of mainly Si and O with a small trace of Al.
