High-energy-resolution grazing emission X-ray fluorescence applied to the characterization of thin Al films on Si

Abstract

The grazing emission X-ray fluorescence (GEXRF) technique was applied to the analysis of different Al films, with nominal thicknesses in the range of 1 nm to 150 nm, on Si wafers. In GEXRF the sample volume from which the fluorescence intensity is detected is restricted to a near-surface region whose thickness can be tuned by varying the observation angle. This is possible because of the refraction of the fluorescence X-rays and the quite long emission paths within the probed sample. By recording the X-ray fluorescence signal for different shallow emission angles, defined relatively to the flat, smooth sample surface, the deposited Al surface layers of the different samples could be well characterized in terms of layer thickness, layer density, oxidation and surface roughness. The advantages offered by synchrotron radiation and the employed wavelength-dispersive detection setup were profited from. The GEXRF results retrieved were confirmed by complementary measurements. The experimental setup, the principles and advantages of GEXRF and the analysis of the recorded angular intensity profiles will be discussed in details.

Depth profiling of low energy ion implantations in Si and Ge by means of micro-focused grazing emission X-ray fluorescence and grazing incidence X-ray fluorescence

“…3, le panel). 23 The dependence of the intensity of a given XRF line on the grazing emission angle is then assessed by rotating the sample around an axis passing through the sample surface plane and being perpendicular to the spectrometer dispersion plane (dened by the axes on which the crystal and detector are moved when a different characteristic XRF line is to be measured). Moreover, the sample was positioned such that the focused synchrotron radiation beam was incident on the rotation axis.…”

Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

“…Such a system can be described with only three parameters, the period p of the pattern and the width l and height h of the individual bricks. From the experimental results concerning samples with dense particle distributions [5][6][7] smooth transitions from particle-like to layer-like structures were expected. In contrast to that, the GO simulations showed very sharp and intense peaks, whose positions were found to vary strongly as a function of the height and period of the pattern.…”

“…In particular they are very useful for trace elements' analysis [6,16], characterization of thin layers [7,17] and depth profiling [18][19][20]. The usefulness of grazing XRF techniques for nanoparticle characterization has also been demonstrated [8,[21][22][23][24][25][26].…”

“…In GEXRF the fluorescence radiation is detected at exit angles around the critical angle [7,[12][13][14][15][33][34][35]. GEXRF can be regarded as an inverted GIXRF experiment where the X-ray source and detector are exchanged (see Fig.…”

“…A further advantage of the GEXRF geometry is the possibility of combining it with wavelength-dispersive instruments for the detection of the fluorescence radiation [6,7,16,39]. This provides a much higher spectral resolution and thus a higher chemical sensitivity.…”