@article{oai:nagoya.repo.nii.ac.jp:00028220,
 author = {Nagamatsu, Kentaro and Ando, Yuto and Kono, Tsukasa and Cheong, Heajeong and Nitta, Shugo and Honda, Yoshio and Pristovsek, Markus and Amano, Hiroshi},
 journal = {Journal of Crystal Growth},
 month = {Apr},
 note = {This study examines the effect of (000−1) GaN substrate misorientation on the residual impurities and surface morphology of N-polar GaN grown by metalorganic vapor-phase epitaxy. Carbon, silicon, and oxygen concentrations decreased with increasing GaN substrate misorientation angle, with the lowest impurity concentration achieved for a misorientation angle of 2° toward the m-axis, with 6×10^15cm^−3 carbon, 6×10^15cm^−3 silicon, and 4×10^17cm^−3 oxygen atoms. The oxygen concentration was measured at a depth of 0.5μm below the wafer surface, and the oxygen concentration decreased with increasing thickness. The incorporation of carbon and oxygen revealed a strong dependence on the misorientation angle. The step distance height of the steps parallel to the [11−20] direction (or perpendicular to the [1−100] m-direction) was confirmed to be a double-height layer step. This phenomenon indicated that m-direction steps are stable for N-polar growth in GaN. In cases of large misorientation toward the m-axis in of the GaN substrate it was difficult to control the misorientation perpendicular to the nominal direction leading to a-axis direction by wafer bowing at wafer manufacturing. Therefore, step-bunching was generated for each symmetric m-axis due to an increase in the compound's off-angle, thus causing the surface roughness to become large., ファイル公開：2021-04-15},
 pages = {78--83},
 title = {Effect of substrate misorientation on the concentration of impurities and surface morphology of an epitaxial GaN layer on N-polar GaN substrate by MOVPE},
 volume = {512},
 year = {2019}
}