[15p-503-1~16] 15.4 III-V-group nitride crystals

△ [15p-503-14] Three-Dimensional Imaging of Threading Dislocations in GaN using Two-Photon-Excitation Photoluminescence Spectroscopy

〇Tomoyuki Tanikawa¹, Kazuki Ohnishi¹, Masaya Kanoh², Takashi Mukai², Takashi Matsuoka¹ (1.IMR, Tohoku Univ., 2.Nichia Corp.)

Keywords:Nitride semiconductor, Threading dislocation, Two-photon-excitation photoluminescence

In this study, we demonstrated three-dimensional imaging of threading dislocations in a thick GaN films using two-photon-excitation photoluminescence spectroscopy. From the emission image, many dark spots were obtained, which were originated by the nonradiative recombination due to the dislocations. The spatial resolution was good enough for the sample with a threading dislocation density less than 10⁸ cm⁻². By changing the focal depth, three-dimensional emission image was built. From this image, the behaviors of dislocation elimination and bending ht dislocation have been evaluated.