Before attempting to submit a GDSII file over 50 MB, first ensure that you have taken advantage of design optimization techniques (e.g., are you taking advantage of GDSII's hierarchical format, such as using cell instances?) in an attempt to reduce the file size. If your design does not lend itself to instancing, and you indeed must submit a large design file, this how-to describes the necessary procedure to do that.

Step-by-step guide

  1. Create a "dummy" GDSII file with the same filename that you will use for your final submission
    • This can be done using the following command: 

      touch $your_filename.gds
  2. Login to LMACS and visit the Photomask section
  3. Upload the "dummy" gds file
  4. Select the appropriate fabrication parameters for your photomask.
    1. For help see: how-to submit a GDSII file
  5. Submit the photomask fabrication request. 
  6. Create an LMACS request of type Administration and in the summary indicate that you have a GDSII file that is too large for conventional submission. Provide the filename associated with your request and any other relevant details, including the file size of your actual GDSII file.
  7. A nanoFAB staff member will respond to your request with details of how to send the file.

The average size of a GDSII file processed by the nanoFAB is approximately 4.46 MB. This is an 11 year average of approximately 2000 files. Of these, 11 have been over 50 MB in size, when those are removed from the calculation, the average size is 2.24 MB. This is to say that the GDSII file format is well suited to convey very complex, and dense geometric information where there is a high level of repetition by using instances. The first this you should attempt to do before submitting a large GDSII file, is revisit your design and ensure that you are taking advantage of this functionality and not submitting a "flattened" design.