TY - JOUR
T1 - Determination of copper nanoparticle size distributions with total reflection X-ray fluorescence spectroscopy
AU - Singh, Andy
AU - Luening, Katharina
AU - Brennan, Sean
AU - Homma, Takayuki
AU - Kubo, Nobuhiro
AU - Nowak, Stanisław H.
AU - Pianetta, Piero
N1 - Publisher Copyright:
© 2017 International Union of Crystallography.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Total reflection X-ray fluorescence (TXRF) analysis is extensively used by the semiconductor industry for measuring trace metal contamination on silicon surfaces. In addition to determining the quantity of impurities on a surface, TXRF can reveal information about the vertical distribution of contaminants by measuring the fluorescence signal as a function of the angle of incidence. In this study, two samples were intentionally contaminated with copper in non-deoxygenated and deoxygenated ultrapure water (UPW) resulting in impurity profiles that were either atomically dispersed in a thin film or particle-like, respectively. The concentration profile of the samples immersed into deoxygenated UPW was calculated using a theoretical concentration profile representative of particles, yielding a mean particle height of 16.1 nm. However, the resulting theoretical profile suggested that a distribution of particle heights exists on the surface. The fit of the angular distribution data was further refined by minimizing the residual error of a least-squares fit employing a model with a Gaussian distribution of particle heights about the mean height. The presence of a height distribution was also confirmed with atomic force microscopy measurements.
AB - Total reflection X-ray fluorescence (TXRF) analysis is extensively used by the semiconductor industry for measuring trace metal contamination on silicon surfaces. In addition to determining the quantity of impurities on a surface, TXRF can reveal information about the vertical distribution of contaminants by measuring the fluorescence signal as a function of the angle of incidence. In this study, two samples were intentionally contaminated with copper in non-deoxygenated and deoxygenated ultrapure water (UPW) resulting in impurity profiles that were either atomically dispersed in a thin film or particle-like, respectively. The concentration profile of the samples immersed into deoxygenated UPW was calculated using a theoretical concentration profile representative of particles, yielding a mean particle height of 16.1 nm. However, the resulting theoretical profile suggested that a distribution of particle heights exists on the surface. The fit of the angular distribution data was further refined by minimizing the residual error of a least-squares fit employing a model with a Gaussian distribution of particle heights about the mean height. The presence of a height distribution was also confirmed with atomic force microscopy measurements.
KW - Cu nanoparticle
KW - grazing-incidence X-ray fluorescence
KW - silicon wafer surface
KW - total reflection X-ray fluorescence
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U2 - 10.1107/S1600577516015484
DO - 10.1107/S1600577516015484
M3 - Article
C2 - 28009568
AN - SCOPUS:85007009178
SN - 0909-0495
VL - 24
SP - 283
EP - 287
JO - Journal of Synchrotron Radiation
JF - Journal of Synchrotron Radiation
IS - 1
ER -