Displaying the results of an XPS Depth Profile

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Displaying the results of an XPS Depth Profile
Laura Blair
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Outline of Presentation

• Review of experiment
• Problem Statement
• What I Did
• What the User has to Do
• Key Features
• Key Issues
• Future Improvements
• Demonstration of programs

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The Experiment

• X-Ray Photoelectron Spectroscopy (XPS) is used to
  evaluate the surface chemistry

Dark therefore less carbon here than in
surrounding region
Bright therefore lots of oxygen compared to
surrounding

• One XPS method is acquiring elemental maps
• Bright regions indicate high intensity whereas
  dark regions indicate low intensity.

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The Experiment

• Find sample Hard disk.
• Collect elemental maps to determine the initial
  surface chemistry.
• Sputter the surface to remove the top nanometers
  (5-20nm). This is done using an ion gun which
  blasts the surface with ions. Different ion gun
  voltage settings are used to control how fast and
  how deep the sputtering occurs.
• Collect elemental maps to determine the surface
  chemistry after the first depth.
• Repeat until you have completed the depth profile
  through the coating in this case it was 13
  layers.

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Problem Statement
Problem Current graphical user interface allows
you to view only one image at a time. The depth
profile conducted for this project resulted in
100 images!
Goal Create a graphical user interface that
would allow me to view a selection of the 100
images at a time making it easier to interpret
the results.
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What I Did
Wrote two programs and two functions to
accomplish objective!

• First Program
• Has one window.
• Has two text fields
• Buttons are element symbols

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What I Did

• Second Program
• Has twelve windows

• Buttons are element symbols and depth values.
• If element symbol selected the program displays
  up to 12 images of that element at different
  depths.

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What I Did

• If depth selected the program displays up to 12
  elements at that depth.

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What I Did

• The two functions are used to extract out the
  element symbols and depth values from text files
  created by the user.
• The extracted information is used by the programs
  to create the buttons and label the images.
• These functions are key in ensuring the programs
  will work when different element symbols, depth
  values, number of elements or number of depths
  are analyzed.

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What I Did Template for depth text file
In the following text document you will need to
enter the number of depths and the values of
each depth in nm On the following line enter
the total number of depths 14 On the following
lines enter the value of each depth in nm only
enter one value per line 0.0 0.78 6.18 11.58 16.98
22.38 27.78 33.18 38.58 56.38 74.18 91.98 109.78
127.58

• Role of the function
• Strip out the comments
• Save depth values to an output file which is
  read by the programs

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What the User has to Do
Conduct a depth profile with maps collected after
each sputter
Create a folder directory in which each folder is
labeled depthn. For example depth0-depth13 in
the example
Open maps in Multipak and adjust endpoints as
necessary
Choose the export as tiff file menu option
Save the file as its elemental symbol in the
appropriate folder.
Create a depth text file or edit the template
text file.
Create an element text file or edit the template
text file.
Compile and run the programs
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Key Features

• Program resizes, crops and labels the images
  prior to display.
• Program versatility doesnt have to be
  re-written for different depth profiles.
• Displays images in a variety of ways allowing
  interpretation from different perspectives.
• Checks to see if image exists before trying to
  display doesnt crash!
• Able to display up to 24 depths and 24 elements.

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Key Features
Oxygen at depth 21 is displayed
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Key Features
Ar is element 17!
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Key Issues

• Program will open images 0-11 first so user wont
  see image 13 if there is also an image 1

• Elemental map collected at depth 0 for all 24
  elements but only 12 displayed

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Key Issues

• Buttons dont wrap around if have 24 elements
  and 24 depths and some buttons will be off the
  screen!

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Future Improvements

• Add save option to the 12 image program so user
  can save display.
• Create a slider for the one image program. I
  created the text widgets so the user can look at
  an individual image but it would be nice if they
  could scroll through all of the images to
  determine which one to study.