Optimization of the structural properties and surface morphology of a convex-graded In$_{x}$Al$_{1-x}$As ($x$ = 0.05–0.83) metamorphic buffer layer grown via MBE on GaAs (001)

The results of optimization of the design and growth conditions of an In$_{x}$Al$_{1-x}$As metamorphic buffer layer with a high In content ($x$ = 0.05–0.83) grown via MBE on GaAs(001) substrates with the purpose of optimizing its surface morphological characteristics and structural properties and lowering the surface density of threading dislocations. The lowest surface-pattern roughness RMS = 2.3 nm (on an area of 10 $\times$ 10 $\mu$m) and density of threading dislocations of 5 $\times$ 10$^7$ cm$^{-2}$ are found in the samples with a convex-graded metamorphic buffer layer.