Nondestructive Angle-resolved X-ray Depth Profiling: Interpretation of Angle-resolved Profiles Using a Monte Carlo Approach

2000 ◽  
Vol 6 (6) ◽  
pp. 517-531
Author(s):  
David K. Wilkinson ◽  
Daniel A. Loveday ◽  
Martin Prutton
Keyword(s):  
Monte Carlo ◽  
Electron Scattering ◽  
Depth Profiling ◽  
Angle Of Incidence ◽  
Beam Angle ◽  
X Ray ◽  
Depth Profiles ◽  
Custom Made ◽  
Measured Angle ◽  
Composition Depth Profile

AbstractA technique has been developed for the interpretation of composition-depth profiles from angleresolved X-ray data using a Monte Carlo electron scattering simulation. This is a nondestructive depth profiling procedure. Software has been developed that uses a Monte Carlo scattering simulation to generate the signal intensity from a multilayer sample for any combination of primary beam angle of incidence and take-off angle to the X-ray detector. An interactive C++ application uses this simulation to interpret measured angle-resolved depth profiles. The method has been tested using a custom-made Ag/Al “staircase” sample containing two layers each of Ag and Al. Using the technique, it is possible to quantify the composition-depth profile for the two- and three-layer “steps” of the sample. Qualitative information may be gained about the four-layer area of the sample.

Angle-Resolved X-Ray Depth Profiling: Interpretation of Angleresolved Profiles Using a Monte Carlo Approach

1999 ◽  
Vol 5 (S2) ◽  
pp. 582-583
Author(s):  
D.K. Wilkinson ◽  
M. Prutton ◽  
D.A. Loveday
Keyword(s):  
Monte Carlo ◽  
Electron Scattering ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Incident Beam ◽  
Angle Of Incidence ◽  
X Rays ◽  
X Ray ◽  
Interaction Volume ◽  
Depth Profiles

A technique has been developed for the interpretation of composition depth profiles from angleresolved x-ray data using a Monte Carlo electron scattering simulation. Conventional methods for the interpretation of angle-resolved depth profiles used in the fields of x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) assume that the outgoing signal is exponentially attenuated along its path. This assumption if not valid for angle-resolved x-ray techniques, as the x-ray signal is dependent on both the paths of the incident electrons and the path of the emitted x-rays. In this case, while the latter can be treated using an exponential attenuation, the path of the incident beam is more complex and corresponds to the well known “pear-shaped” interaction volume. In order to reliably interpret angle-resolved depth profiles in which the angle of the incident beam is varied, it is necessary to be able to obtain the distribution of x-ray emission within the sample for any angle of incidence.

Parallel Monte Carlo Simulation Using Desktop Computers

1999 ◽  
Vol 5 (S2) ◽  
pp. 80-81
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Scattering ◽  
Information Needs ◽  
Image Interpretation ◽  
Scattered Electron ◽  
Electron Trajectories ◽  
X Ray ◽  
Desktop Computers ◽  
Computationally Expensive

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected x-ray and electron signals falls into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation. Such problems are ideally suited to parallel multicomputers, where a manager process distributes the computational burden over a large number of nodes.

scholarly journals Parallel Monte Carlo Simulation Using Desktop Computers

2000 ◽  
Vol 8 (2) ◽  
pp. 34-35
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Scattering ◽  
Information Needs ◽  
Image Interpretation ◽  
Scattered Electron ◽  
Electron Trajectories ◽  
X Ray ◽  
Desktop Computers ◽  
Computationally Expensive

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected xray and electron signals fall into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation.

Rapid Composition-Depth With X-Ray Diffraction: Theory and Practice

1985 ◽  
Vol 29 ◽  
pp. 193-202
Author(s):  
Karl E. Wiedemann ◽  
Jalaiah Unnam
Keyword(s):  
Diffraction Theory ◽  
Lattice Parameter ◽  
Crystal Defects ◽  
Theory And Practice ◽  
X Ray Diffraction ◽  
Parameter Calibration ◽  
X Ray ◽  
Depth Profiles ◽  
Deconvolution Techniques ◽  
Composition Depth Profile

AbstractHigh precision composition-depth profiles can be determined quickly using a recent development. This method requires that noncompositional broadening arising from the instrument, crystal defects, and the radiation source be removed from the diffraction pattern before calculating the composition-depth profile. Effective deconvolution techniques, profiling theory, methodology of profiling, and the effect of residual noncompositional broadening on the profile are discussed. Examples include statistical analyses of error in the profile due to random counting errors and variance in the lattice parameter calibration.

A simple Monte Carlo model for electron-probe quantitation

1992 ◽  
Vol 50 (2) ◽  
pp. 1674-1675
Author(s):  
Peter Duncumb
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Electron Scattering ◽  
Electron Probe ◽  
Monte Carlo Model ◽  
Correction Procedure ◽  
Backscatter Coefficient ◽  
X Ray ◽  
Monte Carlo Techniques

Since the early work of Bishop in the 1960's, many have used Monte Carlo techniques for studying the role of electron scattering in the X-ray production process, but the simulation of individual trajectories has always proved too slow to be of use for online analysis. The paper describes a simple model for calculating the distribution curves of ionisation with depth ϕ(ρz) for a variety of target conditions, which are then characterised by a type of exponential expression capable of much faster computation. This expression is built into a practical correction procedure which can be applied to the analysis of all elements from boron upwards.The Monte Carlo model uses a simple multiple scattering cross-section with 50-step trajectories. This cross-section is adjusted to give the correct variation of backscatter coefficient with target atomic number, as shown in Figure 1, and this is the only physical parameter which it is necessary to fit empirically.

Thermal Behaviour of Implanted Nitrogen and Accumulated Hydrogen in Titanium

1997 ◽  
Vol 504 ◽  
Author(s):  
M. Soltani-Farshi ◽  
H. Baumann ◽  
D. Rück ◽  
G. Walter ◽  
K. Bethge
Keyword(s):  
Ion Implantation ◽  
Depth Distribution ◽  
Depth Profiling ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
Nitrogen Ion Implantation ◽  
X Ray ◽  
Depth Profiles ◽  
Hydrogen Accumulation ◽  
Nitrogen Ion

ABSTRACTThe influence of nitrogen ion implantation on the hydrogen accumulation in titanium was investigated as function of sample temperature and ion fluence. 150 keV nitrogen (15N) ions were implanted at different sample temperatures up to 700°C with fluences ranging from 1 × 1017 to 1 × 1018 ions/cm2. The amount of accumulated hydrogen and its depth distribution was measured quantitatively with the 15N depth profiling method. The implanted 15N depth profiles were measured by the reverse reaction 15N(p, αγ)12C at 429 keV. The binary phases of the implanted nitrogen with titanium are detected by grazing incidence x-ray diffraction. The results are compared with those obtained for samples implanted at RT and subsequently thermally treated.

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