Abstract
A major obstacle to achieving high-performance devices using nonpolar a-plane and m-plane GaN is the existence of high-density threading dislocations and stacking faults. Low-defect-density nonpolar plane GaN films were previously grown by sidewall epitaxial overgrowth using metalorganic vapor phase epitaxy [1, 2]. In this study, we control the growth-rate ratio of Ga-polar GaN to N-polar GaN by adjusting the V/III ratio. It is possible to grow GaN only from the N-face sidewall of grooves by maintaining a high V/III ratio, which reduces the number of coalescence regions on grooves and decreases the threading-dislocation density and stackingfault density.