• Combined Pulsed RF GD-OES and HAXPES for Quantified Depth Profiling through Coatings

      Bouttemy, Muriel; orcid: 0000-0001-5907-2576; email: muriel.bouttemy@uvsq.fr; Béchu, Solène; email: solene.bechu@uvsq.fr; Spencer, Ben F.; email: ben.spencer@manchester.ac.uk; Dally, Pia; email: pia.dally@ipvf.fr; Chapon, Patrick; email: patrick.chapon@horiba.com; Etcheberry, Arnaud; email: arnaud.etcheberry@uvsq.fr (MDPI, 2021-06-11)
      Chemical characterization at buried interfaces is a real challenge, as the physico-chemical processes operating at the interface govern the properties of many systems and devices. We have developed a methodology based on the combined use of pulsed RF GD-OES (pulsed Radio Frequency Glow Discharge Optical Emission Spectrometry) and XPS (X-ray Photoelectron Spectroscopy) to facilitate the access to deeply buried locations (taking advantage of the high profiling rate of the GD-OES) and perform an accurate chemical diagnosis using XPS directly inside the GD crater. The reliability of the chemical information is, however, influenced by a perturbed layer present at the surface of the crater, hindering traditional XPS examination due to a relatively short sampling depth. Sampling below the perturbed layer may, however, can be achieved using a higher energy excitation source with an increased sampling depth, and is enabled here by a new laboratory-based HAXPES (Hard X-ray PhotoElectron Spectroscopy) (Ga-Kα, 9.25 keV). This new approach combining HAXPES with pulsed RF GD-OES requires benchmarking and is here demonstrated and evaluated on InP. The perturbed depth is estimated and the consistency of the chemical information measured is demonstrated, offering a new route for advanced chemical depth profiling through coatings and heterostructures.