9:15 AM - 9:30 AM
▲ [21a-E319-2] An atomic-level insight into the surface step edge of GaN
Keywords:Gallium nitride, Power device, Density functional theory
GaN is becoming the best candidate for the next leap forward in modern power electronic devices. Metalorganic vapor phase epitaxy (MOVPE) is nowadays the most accredited method for mass production of high-quality GaN. Hence, detailed knowledge of the growth mechanism in MOVPE under frequently used gas condition is highly desirable. In this presentation, we have investigated the step edge structure of GaN based on density functional theory. Four distinct types of GaN step edge model depending on whether the edges are terminated by Ga or N are considered and their atomic-level structure is analyzed with special emphasis on the edge termination, which can carry either Ga or N. Since the growth surface is H covered occasionally, hereafter denoted as the 3 GaH structure, we examined all the possible arrangements of H atoms on the terrace. The electron counting rule is applied to define the energetically most favorable configuration.