Deformation state of short-period AlGaN/GaN superlattices at different well-barrier thickness ratios

Abstract

Dependence of deformation characteristics changing in superlattice (SL) structures AlxGa₁₋xN/GaN with Al (~10%) on the well-barrier thickness ratio in period was studied in this work. The deformation state of SL and individual layers, relaxation level and periods, layers’ thickness and composition of AlxGa₁₋xN layers were analyzed using high-resolution X-ray diffractometry. It was ascertained that the buffer layer and SL layers are compressed in all the investigated structures. Thus, it has been shown that deformation of the SL period depends on the well/barrier thickness ratio. Thicknesses of individual layers in SL strongly depend on the deformation state of the whole system. Increasing the deformation level leads to the increase of the barrier layer thickness.