Saturation effects in TXRF on micro-droplet residue samples

Trends in total reflection X-ray fluorescence spectrometry for metallic contamination control in semiconductor nanotechnology

“…8 [40,41]. The saturation effect is explained quantitatively by the phenomenon of mass-absorption of the primary X-ray beam in the residue, as demonstrated in a recent modeling study [41]. The saturation effect is found to be depending on both sample characteristics, such as the density and the residue dimensions, and analysis settings such as the excitation energy.…”

“…3-10 ng), as illustrated in Fig. 8 [40,41]. The saturation effect is explained quantitatively by the phenomenon of mass-absorption of the primary X-ray beam in the residue, as demonstrated in a recent modeling study [41].…”

“…7a) [12,75]. -The low linear range of TXRF on the micro-droplet samples, limited to less than four orders of magnitude: The upper limits of the range are determined by the effects of massabsorption of primary X-rays in the residue, as demonstrated very recently [41]. As the droplet drying process inherently leads to compact ring-shaped residues with rather high metal densities, mass-absorption effects start to be significantly (underestimations >10%) already above low metal contents of about 3 × 10 13 -1 × 10 14 Ni atoms depending on the excitation source (i.e.…”

Picoliter solution deposition for total reflection X-ray fluorescence analysis of semiconductor samples

“…Previous experiments with 20 nL droplet size showed a linearity of TXRF signal response up to 20 ng total Ni in the array [20], which was an improvement in the linearity range over previously reported dried residues measured by TXRF [10,11]. The linearity range of the picoliter droplet arrays was studied by jetting a pattern of 88 × 87 depositions of 9 pL droplets, for a total of 7656 droplets in each array.…”

“…This level of automation, while possible with VPD-ICP-MS, is more difficult to achieve and thus it is usually regarded as a laboratory analysis. Even though automated VPD-TXRF systems are widely accepted in the semiconductor industry [7][8][9] there are areas for improvement such as expanding the linear dynamic range and controlling the morphology of the dried residue as that impacts the analytical signal [10][11][12][13][14][15][16][17]. The morphology has critical influence on effects like absorption of the fluorescence photons of the primary beam and therefore on the accuracy of the analysis.…”