The nanoFAB provides fabrication services for 5” × 5” and 7” × 7” photomasks, for use in contact mask aligners. A photomask is a key component in many fabrication processes, as it is used to define the pattern transferred during photolithography.  At the nanoFAB, we also provide access to CAD software and training resources that you can use to design your photomask onsite. You can also design your mask using any software capable of producing a GDSII file (the filetype required for submission); however, we are unable to provide support should you run into problems with another CAD system.

The physical properties of the masks produced in the nanoFAB are:

  • Dimensions:  5” × 5” × 0.090” or 7” × 7” × 0.090”
  • Material:  soda-lime glass (suitable for g/h/i-line and broadband photolithography)
  • Chrome coating:  ~100 nm thick low-reflectivity chromium (~11% reflectivity at 436 nm wavelength)
  • The minimum achievable feature size (critical dimension, CD) depends on the maskwriter lens, which is selectable upon mask submission:
    • 10 mm lens:  2 µm CD
    • 4 mm lens:  1 µm CD

The first step to submitting a photomask for fabrication is to register as a nanoFAB user. Once you have completed the account registration steps, you can proceed to the steps below.

1.  Authorize mask submission

Due to the relatively high cost of photomask fabrication, submission must be authorized by the project or group manager for each project under which a mask fabrication request is being submitted:

2.  Get trained on GDSII pattern design (optional)

The nanoFAB only accepts photomask files in GDSII (.gds) format.  Please see the following for various options for generating and editing GDSII files, including tutorials for both GUI- and script-based approaches:

3.  Submit a GDSII file via LMACS

Photomask design files in GDSII format can be submitted by authorized users via the Photomasks panel in LMACS:


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