Dislocation Reactions in a Semipolar Gallium Nitride Layer Grown on a Vicinal Si(001) Substrate Using Aluminum Nitride and 3C–SiC Buffer Layers

Abstract

Transmission electron microscopy was used to study the interaction of a + c and a dislocations in a thick (14 μm) semipolar GaN layer grown by hydride vapor phase epitaxy on a 3C-SiC/Si(001) template. It is shown that the propagation of a dislocation half-loop with a Burgers vector b = $\frac{1}{3}\left\langle {1\bar {2}10} \right\rangle$ during cooling can be blocked due to its reaction with a threading dislocation with a Burgers vector b = $\frac{1}{3}\left\langle {\bar {1}2\bar {1}3} \right\rangle$ with the formation of a dislocation segment with a Burgers vector b = 〈0001〉. The gain in energy of the system as a result of such reaction is theoretically estimated. Within the approximation of dislocation linear tension, this gain is ~7.6 eV/Å, which gives ~45.6 keV for new dislocation segment with a length of ~600 nm. The contribution of the energy of the dislocation core is estimated as ~19.1 keV.