The challenge to get correct oxide thickness from depth profiling is to calibrate the sputter rate just for your material. You basically need to have CuO sample preferably in the thin film form and sputter through the entire layer.

If the oxide is not thicker than 5-10 nm you could use the ARXPS as suggested above or make an estimate based on the signal intensities of oxide and metal peaks.

Dear Dr. Anis Aliouat,

I send you the details of the following, interesting article, that I think can be useful for your research as a source of numerous information:

-Oxidation of Polycrystalline Copper Thin Films at Ambient Conditions

Ilia Platzman, Reuven Brener, Hossam Haick and Rina Tannenbaum

J. Phys. Chem. C, 112, 4, 1101-1108 (2008)

https://doi.org/10.1021/jp076981k

Available at: https://pubs.acs.org/doi/full/10.1021/jp076981k?src=recsys

I suggest also to have a look also at the discussion "How to measure the oxide film thickness on Cu-Ni (90/10) alloy corrosion in seawater by using XPS depth profiling?" present in RG at: https://www.researchgate.net/post/How_to_measure_the_oxide_film_thickness_on_Cu-Ni_90_10_alloy_corrosion_in_seawater_by_using_XPS_depth_profiling

XPS analysis is also able to provide qualitative / quantitative information regarding the elements present in the extreme surface area (2-5 nm). This interval depends upon the kinetic energy of the electrons and the material being analyzed In your case, knowing the composition of the different layers that make up your sample, performing a "weak" and controlled etching, you could go back - by consulting the suitable scientific bibliography - to an "approximate" thickness. You could also try Angle-resolved XPS (ARXPS); it is a technique that varies with the emission at the electrons are collected, thereby enabling electron detection from different depths. ARXPS provides information on the thickness and composition of ultra-thin films. Such measurements are non-destructive, unlike sputter profiling.

For further information, you can see at: https://xpssimplified.com/angle_resolve_xps.php

Good work and best regards, Pierluigi Traverso

The challenge to get correct oxide thickness from depth profiling is to calibrate the sputter rate just for your material. You basically need to have CuO sample preferably in the thin film form and sputter through the entire layer.

If the oxide is not thicker than 5-10 nm you could use the ARXPS as suggested above or make an estimate based on the signal intensities of oxide and metal peaks.

Beside that you have to know the source of your Oxygen peak. is it adsorbed oxygen or lattice oxygen.