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

摘要

Transmission electron microscopy was used to study the interaction of a + c and a dislocations in a thick (14 mu m) 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 = 1/3 < 1 (2) over bar 10 > during cooling can be blocked due to its reaction with a threading dislocation with a Burgers vector b = 1/3 <(1) over bar2 (1) over bar3 > 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 similar to 7.6 eV/angstrom, which gives similar to 45.6 keV for new dislocation segment with a length of similar to 600 nm. The contribution of the energy of the dislocation core is estimated as similar to 19.1 keV.