Detection angle resolved PIXE and the equivalent depth concept for thin film characterization

Abstract

The characterization of thin films using PIXE, although basically a simple matter, in practice suffers from significant problems. Here two case studies are presented in which the use of grazing detection geometry is shown to be a good solution. The first case study, the analysis of GaSb-InAs films deposited on a GaSb substrate, relates to the measurement of elements of atomic number close to and below that of the substrate. Problems may be due to the tail of the peaks that correspond to x-rays emitted from the substrate, and also to the presence in the substrate of an element having large x-ray emission cross-sections. The use of the simulation capability implemented on the DATTPIXE package is shown to be of good help in the proper planning of the analysis procedure. In the second case study, the distinction between film contamination and substrate material contamination is discussed. In this case the characterization of a ZnO film deposited on sapphire is presented. The concept of equivalent depth is discussed and it is shown to be an important tool for a straightforward distinction between film and bulk contamination

Dependence of relative intensity of L1 sub-shell X-rays on ion beam energy

“…The ITN PIXE setup, described in detail elsewhere [9], makes use of a Si(Li) 150 eV resolution detector kept at an angle of 110°r elative to the beam direction. In the case of this experiment, a Ta collimator with a thickness of 1 mm and a diameter of 0.7 mm was used in front of the Si(Li) detector.…”

PIXE analysis of multilayer targets

“…In respect to the specific applications, these properties already are important for many different fields. Two examples of these are (1) human heritage, where the analysis of artefacts covered by thin metallising layers, or the characterisation of paintings layers6 are an important issues and (2) energy production, where the characterisation of films involving close atomic number elements and used in the production of thermophotovoltaic devices,7–9 is a major problem. Still, these are just specific cases of the more general condition where complex in‐depth inhomogeneous samples must be characterised.…”

L X-Rays RYIED Oscillations and Proton-NMRD of Gd2O3 Nanoparticles

“…Once ready, the samples were placed in the irradiation chamber under vacuum, to assure that no degradation or contamination would arise from atmospheric exposure, which was thus limited to a very few minutes necessary for closure and evacuation of the irradiation chamber. The experimental facilities details can be found elsewhere [22]. High statistics spectra were collected (roughly 200 000 counts in the L α ) for proton energies from 700 keV to 1450 keV in steps of 50 keV, and for 1700 keV and 1950 keV.…”