We investigated the effects of SiN<sub>x</sub> interlayers on the structural and electrical properties of nonpolar <i>a</i>-plane (11-20) GaN grown on <i>r</i>-plane (1-102) sapphire substrates by metal–organic chemical vapor deposition (MOCVD). The Nomarski optical microscope images showed that the deposition conditions of the SiN<sub>x</sub> layer could strongly affect the <i>a</i>-plane GaN surface morphology due to the different SiN<sub>x</sub> coverage. Basal-plane stacking faults (BSFs) and threading dislocation (TD) densities were reduced in the <i>a</i>-plane GaN samples with high SiN<sub>x</sub> coverage and multiple SiN<sub>x</sub>-treated GaN interlayers. These results indicate that TD reduction is associated with an increase in the 3D growth step and with the blocking of TD propagation. From on-axis (11-20) X-ray rocking curve (XRC) measurements, the anisotropy of full width at half maximum (FWHM) can be attributed to the crystal mosaicity due to insertion of different SiN<sub>x</sub> interlayers. The anisotropy of sheet resistance between the <i>c</i>-and <i>m</i>-axis was also clearly seen in a-plane GaN samples with a high density of defects, which was attributed to the BSFs as scattering centers.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ji Hoon Kim ; Sung-Min Hwang ; Yong Gon Seo ; Doo Soo Kim ; Kwang Hyeon Baik, et al.
"Effect of SiNx interlayer on structural and electrical properties of nonpolar a-plane (11-20) gallium nitrides", Proc. SPIE 8484, Twelfth International Conference on Solid State Lighting and Fourth International Conference on White LEDs and Solid State Lighting, 84840H (December 11, 2012); doi:10.1117/12.929523; http://dx.doi.org/10.1117/12.929523