The development of ultraviolet light-emitting diodes (LEDs) hinges on the precise control of the atomic composition within AlGaN-based heterostructures. To analyze this composition, we employed angle-resolved X-ray photoelectron spectroscopy (AR-XPS) combined with Ar gas cluster ion source (ArCIB) sputtering for depth profiling on AlN(0001), AlGaN(0001), and AlGaN quantum dot surfaces. Core level shifts were determined using both Al Kα and Ag Lα photon sources. The study revealed that sputtering with Ar1000+ ion clusters at 10 keV energy created surface disorder and altered the atomic composition. This damage impacted depth profiling with the surface-sensitive Al Kα source. However, utilizing the less surface-sensitive Ag Lα source with its higher photon energy effectively suppressed the contribution from the damaged surface layer. This combination of GCIS sputtering and Ag Lα line XPS measurements proves highly promising for accurately quantifying the atomic composition in buried epitaxial layers or heterostructures with thicknesses of several tens of nanometers.
