Displaying the results of an XPS Depth Profile

Laura Blair

Outline of PresentationReview of experiment

Problem Statement

What I Did

What the User has to Do

Key Features

Key Issues

Future Improvements

Demonstration of programs

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

The Experiment

•One XPS method is acquiring elemental maps

•Bright regions indicate high intensity whereas dark regions indicate low intensity.

Bright therefore lots of oxygen compared to surrounding

Dark therefore less carbon here than in surrounding region

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.

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.

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

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.

What I Did

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

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.

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 depths14# On the following lines enter the value of each depth in nm# only enter one value per line0.00.786.1811.5816.9822.3827.7833.1838.5856.3874.1891.98109.78127.58

Role of the function:

• Strip out the comments

• Save depth values to an output file which is read by the programs

What the User has to DoConduct a depth profile with maps collected after each sputter

Open maps in Multipak and adjust endpoints as necessary

Choose the export as tiff file menu option

Create a folder directory in which each folder is labeled depthn. For example depth0-depth13 in the example

Save the file as it’s 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

Key FeaturesProgram resizes, crops and labels the images

prior to display.

Program versatility – doesn’t 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 – doesn’t crash!

Able to display up to 24 depths and 24 elements.

Key Features

Oxygen at depth 21 is displayed

Key Features

Ar is element # 17!

Key Issues•Program will open images 0-11 first so user won’t see image 13 if there is also an image 1

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

•Buttons don’t wrap around – if have 24 elements and 24 depths and some buttons will be off the screen!

Key Issues

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.