“…Generally, cone-shaped nanoparticles or nanorods are found in etched c-GaN. 24,25 However, in the case of m-GaN, those shapes were not observed, and the surface of the m-plane remained flat with almost no etching because the easily etched dislocations were formed parallel to the growth plane in the crystal structure of m-GaN. However, in the pro-cess of m-GaN growth, vertical SFs also occur and are affected by the etching.…”