Application of soft X-ray reflectometry for analysis of underlayer influence on structure of atomic-layer deposited SrTixOy films

Abstract

We explored the possibility to quantify the atomic in-depth distributions by using the energy-dependent soft X-ray reflectivity (SXRR) measurements, in particular, the possibility to obtain the profiles of low-Z elements [C, N, O, Si] in heterostructures containing high concentration of higher-Z atoms [Ti, Sr, Hf]. We have shown that the SXRR technique allows one not only to quantify the atomic composition of the Sr-rich SrTixOy insulators grown on (100)Si by the Atomic Layer Deposition method but also to obtain atomic profiles across a few-nm thick underlayer (UL) inserted between SrTixOy film and the Si substrate. The accuracy of atomic concentrations and densities estimated is already sufficient to trace even small variations in composition of the SrTixOy grown by ALD on the chemically different underlayers and most it is important the composition and extension of an interfaces.