Mass transport and thermal stability of TiN/Al2O3/InGaAs nanofilms

The structure of TiN/Al2O3 nanofilms grown on InxGa1-xAs substrates was studied with angle-resolved x-ray photoelectron spectroscopy (ARXPS), high resolution transmission electron microscopy (HRTEM), and density functional theory calculations. From the ARXPS studies, it was possible to characterize in detail the composition and distribution of the various layers constituting the nanofilms; the results were consistent with HRTEM micrographs. The analysis of the ARXPS data showed that annealing causes diffusion of indium atoms from the substrate into the titanium layer. It also allowed for establishing that the thickness and composition of the dielectric layers remain stable under thermal treatments.