Use Matlab to set up mathematical modeling of physics
Learning about creating of silicone computer chips using lithography
Matlab exercises for understanding how to code the problem, understanding the problem
This was only the first week of the internship and I have already learned so much. On the second day, we were given sample absorption profiles. These are 2d gratings that are used to diffract the UV light that is used in the lithography process for patterning silicon based logic boards. We start with the assumption that the light is going straight down to towards the surface of the material, and from there model the system in MatLab. We utilized the CXRO (Center for X-Ray Optics) website in order to get the properties of these particular materials to set the parameters in MatLab. Much of our time was spent trying to understand how to model the phase shift of the light accurately in MatLab.
Model the problem with more complexity to better simulate the process.
Practice getting the desired outcome.
Week two of the internship has me feeling excited, fullfilled, and proud of my abilities. I learned how to utilize a GitHub repository and package manager to manage dependencies. This was difficult to coordinate with my colleagues because none of us had ever done this before. But since our mentor form CXRO had written so many helper functions for the more complex mathematical modeling, it was important that we were able to pull the newest versions of his code and stay up to date. As the week progressed, the functions had to be changed to become more adaptable and accurate, taking into account my group’s suggestions for improvement. We continued with the first week’s line of inquiry, but added the complexity that light enters at a slight angle and bounces off a mirror. We plotted the contrast of our pattern as a result of material thickness. The context was affected by the gradient caused by the light entered at an angle. On the second day, I found an interesting Easter egg in MatLab. If you ask it to draw something without giving sufficient information, a picture of a young boy’s face is applied to it. I didn’t have time to investigate further, but I found this interesting, and will add a picture here later.
Fine-tune the model to determine ideal conditions.
Prepare presentation on the module.
Learn how to program a segment of circuitry for use in an actual chip.
This week I have been putting everything we've learned to good use as we finish up the first module. My colleagues and I have been collaborating on writing code. I really enjoy seeing how other people work through problems. We worked together to write a code for finding the optimal threshold for light, to represent how much chemical resist we need to react with the light. I suggested a very pertinent modification to the code which allowed for reproducible photon effects vital to calculating the roughness. Sparing the technical details, I froze the photons in a moment of time, rather than getting new randomly placed photons everytime through a loop. By the end of the week, we chose different sets of materials to examine for utility in this lithography process and investigated them in groups. Miraculously, we were ready to present our findings by Friday afternoon. Since we put in so much work creating models, the analysis went comparably smoothly.
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