[13p-A302-1~10] 15.4 III-V-group nitride crystals

▲ [13p-A302-10] First-principle study of structures and energetics of atomic steps on GaN(0001) surface

〇(P)ThiKieuMy Bui¹, Kenji Shiraishi^1,2, Atsushi Oshiyama¹ (1.IMaSS, Nagoya Univ., 2.Grad. School of Engineering, Nagoya Univ.)

Keywords:Gallium nitride, Step, Density functional theory

Gallium Nitride (GaN) is emerging as a candidate for the next generation of power switching applications owing to the material's superior properties. For a massive production of GaN devices, high-quality epitaxial GaN films are required. MOVPE is well-known to be the best method for a mass production of high quality GaN films. In MOVPE, the growing surface under N₂ carrier gas condition was identified as the Ga rich surface. In this presentation, we have systematically investigated the structural stability of mono-bilayer atomic steps on the Ga rich GaN (0001) surface. We have found that the more Ga-Ga bond is formed at the step edge, the more stable that system is. Our previous calculation shows that Ga-Ga weak bonds is the hotspot for the N incorporation, thus the step edge in which there are Ga-Ga weak bonds may promote N incorporation, or in another word, enhance GaN thin film growth, in accordance with the generally observed step-flow epitaxy.