Effect of high Al-content AlGaN/GaN short period strained-layer superlattices on the threading dislocations in GaN films

In this paper, we report the role played by AlGaN/GaN short period strained-layer superlattices (SPSLS) on the threading dislocation (TD) density reduction in GaN films. TD annihilation and de-multiplication processes were observed to account for the etching pit densities (EPD) reduction in GaN films involving AlGaN/GaN intermediate SPSLS structures. Transmission electron microscopy (TEM) was employed to characterize the microstructural properties of GaN films.