[21p-146-1~17] 15.4 III-V-group nitride crystals

[21p-146-8] Dislocation Characteristics in GaN Substrates by Single Point Seed Na-flux Method

〇Hiroyuki Mizuochi¹, Yoshiyuki Tsusaka^1,2, Junji Matsui², Masayuki Imanishi³, Yusuke Mori³ (1.Grad. Sch. of Material Sci., Univ. of Hyogo, 2.Syn. Rad. Nano-Tech. Center, Univ. of Hyogo, 3.Grad. Sch. of Eng., Osaka Univ.)

Keywords:bright-field X-ray topography under multiple-diffraction conditions, GaN growth by Na-flux, dislocations

We characterized the dislocations in single point seed Na-flux GaN substrates by means of bright-field X-ray topography under multiple-diffraction conditions. Although the species including the seed in an early growth stage reveal many dislocations, dislocation densities become less and less in late growth stages since the dislocations propagate to the crystal side plane. It is found that basal dislocations originate at the sites of the dislocations existing in inclined planes. Based on the contrast disapperance rule of the X-ray topography, Burgers vectors of the basal dislocations are determined to be a (1/3<11-20>type).