Full text loading...
Surface SEM images of (a) as-grown -GaN film and (b) ambidirectional islands at the initial nucleation stage. (c) Surface morphology after KOH wet-etching within the dotted line of sample (a).
SEM images of -GaN films grown on various -sapphire substrates. (a) inclined toward the direction by 1°, (b) on-axis, (c)–(f) are inclined toward the direction by 1°, 2°, 3°, and 5°. The  direction of GaN is marked by the black arrow and the inclined direction of -sapphire is marked by the red dotted arrow. Insets are UV microscope images for IT -GaN buffer layers prior to the growth of HT -GaN. An increase in pit density with increasing of the off-cut angle of the -sapphire is observed.
X-ray diffraction rocking curve FWHMs for -GaN films as a function of off-cut angle and direction of -sapphire.
(a) AFM image of -sapphire with off-cut angle of 2° toward an -plane direction after annealing and schematic illustration of the surface potential energy for an adsorbed adatom on stepped surface . Schematic drawing of the -GaN crystallites grown on -sapphire substrates inclined toward the (b) direction and (c) direction of an -sapphire.
Article metrics loading...