Study of In0.53Ga0.47As/InP interface in III–V heterostructures by coupling monoatomic argon sputtering and high-energy x-ray photoelectron spectroscopy

Abstract

The non-destructive characterization of the buried InGaAs/InP interface is implemented using a combination of argon (Ar+) sputtering and high-energy x-ray photoelectron spectroscopy (HAXPES). HAXPES is not surface sensitive but rather volume sensitive, so we can model the HAXPES peak intensities by neglecting the surface damage to InGaAs caused by argon sputtering. This modeling allowed a precise location of the HAXPES in-depth analysis after sputtering, in terms of InGaAs and InP probed thicknesses, as well as an estimation of the relative elemental concentrations. An experimental study of the HAXPES peaks showed the abruptness of the InGaAs/InP interface, free of element interdiffusion, and enabled the quantification of the composition of the InGaAs layer. The abruptness of this interface is also confirmed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and scanning transmission electron microscopy-energy dispersive x-ray (STEM-EDX) analyses. ToF-SIMS profiles acquired with a depth resolution of 1.5 nm showed rather abrupt profiles, and STEM-EDX confirmed homogeneous compositions and flat interface.