Improved Semipolar (11$\bar{2}$2) GaN Quality Grown on $m$-Plane Sapphire Substrates by Metal Organic Chemical Vapor Deposition Using Self-Organized SiN$_{x}$ Interlayer
1Key Laboratory of Wide Band-Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071 2School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071
Abstract：The effect of a self-organized SiN$_{x}$ interlayer on the defect density of (11$\bar{2}$2) semipolar GaN grown on $m$-plane sapphire is studied by transmission electron microscopy, atomic force microscopy and high resolution x-ray diffraction. The SiN$_{x}$ interlayer reduces the $c$-type dislocation density from $2.5\times10^{10}$ cm$^{-2}$ to $5\times10^{8}$ cm$^{-2}$. The SiN$_{x}$ interlayer produces regions that are free from basal plane stacking faults (BSFs) and dislocations. The overall BSF density is reduced from $2.1\times10^{5}$ cm$^{-1}$ to $1.3\times10^{4}$ cm$^{-1}$. The large dislocations and BSF reduction in semipolar (11$\bar{2}$2) GaN with the SiN$_{x}$ interlayer result from two primary mechanisms. The first mechanism is the direct dislocation blocking by the SiN$_{x}$ interlayer, and the second mechanism is associated with the unique structure character of (11$\bar{2}$2) semipolar GaN.
2016, Vol. 33 
