[11a-PB4-1~18] 15.4 III-V-group nitride crystals

▲ [11a-PB4-16] Characterization of a GaN wafer and a homo-epitaxial layer by synchrotron X-ray topography techniques

〇(PC)Okkyun Seo¹, Jaemyung Kim¹, Satoshi Hiroi¹, Yoshihiro Irokawa¹, Toshihide Nabatame¹, Yasuo Koide¹, Osami Sakata¹ (1.NIMS)

Keywords:X-ray topography, Lattice orientational mapping, GaN and homo-epitaxial layer

We have investigated the crystal quality of the 2 and 4-inch GaN wafer and homo-epitaxial layer by monochromatic X-ray diffraction topography. GaN (11-24) diffraction images at various incident angles were obtained to determine the image of maximum intensity and full-width at half-maximum (FWHM). [1-3] In addition, we have investigated the local structures of a GaN substrate through an energy-resolved white X-ray diffraction topography method. A section topography geometry was implemented at various sample positions for the purpose of wafer mapping. The obtained images at each position were piled up for the 3D matrix then sliced at a same energy position. The sliced images of the lower and higher diffraction energy showed periodic bottom-less and top-less features originated from the local lattice tilting, respectively.