Sandra You

Weekly Update #4

1. What was accomplished:

   1. Re-patterned chip with the mask created from Update #2.

      1. Re-measured using the calibrated microscope measurements, but noticed large discrepancy between the 10x and 20x measurements, as shown below.

         1. Points at 45 units and 80 units were measured using the 10x magnification, while other points were measured using 20x magnification.

         2. May need to re-calibrate then re-measure.

      
   2. Patterned chip to try and test alignment using the below mask:

      

      1. When patterning, it was difficult to align the masks exactly.

         
   3. Completed mask generation for pad resistance/Metrology team collaboration (pending their approval).

      1. Will be testing 4 different pad sizes with 4 different n-channel sizes. 250 um x 250 um pad size masks shown below.

         
   4. Explored Magic VLSI but Icey suggested gdsCAD and KLayout as more modern alternatives. Will summarize benefits and tradeoffs of each tool during demo.

2. Roadblocks:

   1. Alignment of masks for patterns that require multiple exposures is difficult: will discuss in demo.

      1. Would be nice to have a way to place markers on the stepper or have exact distance tracking, but that's probably difficult to implement.

      2. Purpose of alignment tests is to discover whether overlap in exposures causes unexpected behavior when photoresist is developed, which would create the need for certain DRC rules.

3. Plans for next week:

   1. Finalize and present demo slides on demo day.

   2. Incorporate feedback from demo day and collaborate with the Metrology and Stepper team to determine next steps.

   3. Select one tool from the explored options (gdsCAD, KLayout, etc.) to focus on and deepen understanding.

   4. Calibrate and re-measure the scale factor test to ensure proper calculation.

Weekly Update #3

1. What was accomplished:

   1. Patterned chip following the Patterning SOP with mask created from Update #2 on Thursday work session.

      1. Were not able to calibrate the microscope to take accurate measurements of sizing because calibration slider wasn't available.

      2. Best fit line suggests 1 unit in phidl is equal to 1.21 um for the microscope, with 0.144 um as the y-intercept, but the microscope is not calibrated.

      
   2. Created functions that can generate the cross alignment pattern on a mask, and generate NMOS masks at different locations on the mask.

      1. https://colab.research.google.com/drive/1bXM5GX_AE7WAsoSxQLe35XEuIYxSi_KF?usp=sharing

   3. Created notes on Magic VLSI Tool; Found promising information for possible integration with Hacker Fab processes.

2. Roadblocks:

   1. Calibration slider for microscope seems to have been lost, so we don't know the exact measurements of our masks on the chip and therefore cannot get the scale factor. For now, we will use the scale factor estimation from Kent and the measurements we've taken.

3. Plans for next week:

   1. Will work with the Metrology/Packaging team to deliver Resistor lab pattern but with pads added on at the peripheral

   2. Look more into Magic VLSI, complete tutorials, and discuss with Icey to see if this is a promising path to go down.

   3. Determine a good method/formula to generate resistors (single segment vs. multiple), function to size NMOS differently, and learn the masks/patterns for a capacitor.

Weekly Update #2

1. What was accomplished:

   1. Created a mask with rectangles of various sizes to test scale factor of phidl grid units to micrometers.
   2. Learned how to use the stepper, and SOP for patterning.

   3. Talked to the stepper team and decided on a cross with 1 elongated side as the marker shape of choice for now.

   4. Generated code that turns GDSII files into a png.

2. Roadblocks:

   1. Gina and I went into lab Sunday night to learn how to pattern, but the spin coater was unusable due to the vacuum being too weak.

      1. We were unable to actually pattern a chip and measure the scale factor of grid units to micrometers.

3. Plans for next week:

   1. Pattern a chip with the mask above, and measure the sides of each rectangle to determine the scale factor.

   2. Research Magic VLSI tool.

   3. Learn more about phidl layers, and how to implement them for more complex masks.

Weekly Update #1

1. What was accomplished:

   1. Determined that I would be working with Gina on mask automation and DRC rules.

   2. Planned out the semester week-by-week with action items for the Project Proposal. (https://docs.google.com/document/d/1wVFeGedLbJkedMMWSoLg0EdzVot8mtU53Ke8EUfJB6Y/edit?usp=sharing)

   3. Looked over the current progress and code for mask generation and DRC rules in the HackerFab Git repo.

2. Roadblocks:

   1. Gina and I will need to begin fabrication of single layers to determine the aspect ratio of the current mask generation code, but we have not had a lab session yet.

      1. With Lab 1 next week, we hopefully will learn how to create a single layer, and be able to test different unit lengths in the current mask generation code.

3. Plans for next week:

   1. Learn how to fabricate single layers.

   2. Look more into phidl, graphics packages that allow for users to input or drag and drop shapes, and some examples of DRC rules.

   3. Experiment with exporting jpg files from the current mask generation code.

Weekly Update #0:

1. What was accomplished:

   1. Read over EDA primer and looked into the resources linked.

   2. Did some searching on adding pdk to Cadence.

2. Roadblocks:

   1. No roadblocks at the moment.

3. Plans for next week:

   1. Figure out how to help the EDA team this semester.

      1. Currently thinking of creating a template for Cadence pdk files.