MULTIPLE CHARACTERIZATION OF STRUCTURAL PERFECTION IN GaAs/AlAs SUPERLATTICE

A small angle X-ray diffraction using synchrotron radiation, microscopic Raman spectroscopy and a high-resolution TEM were used to characterize superlattices (SLs) grown at 500, 600, and 700°C. The periodicity of the SLs was not degraded, but transition-layer thickness increased with the growth temperature. The transition layer was revealed to be atomic-layer steps with a monolayer per length >100 A for the 500°C-, and with one or two monolayers per length less than 30 A for the 700°C-grown SLs