Photomasks at BNC are made on the /wiki/spaces/BNCWiki/pages/6228442 using a laser direct write process. The mask production process flow is:
Design: Researcher designs layout in GDS, CIF, or DXF format using CAD program of choice.
- Submission: Researcher submits a Photomask Fabrication Request in the Request Services tab in the BRK Lithography Core iLab page.
Direct link to submit a new Photomask Fabrication Request: https://purdue.ilabsolutions.com/service_item/new/4127?spt_id=9351 Verification: Staff converts layout into Heidelberg specific LIC file on cleanroom PC.
- Acceptance: Researcher meets with staff in cleanroom or staff offices to inspect translated file and give final approval.
- Fabrication: After final approval, masks will be completed within 5 business days. Fabrication consists of:
- Writing: Staff member writes the appropriate plate on the Heidelberg, with total write time depending on the size of the design (the Heidelberg writes at ~12 mm2/min).
- Wet Processing: The written plate is developed, etched, and the remaining PR is removed.
- Inspection: Minimum feature size is inspected and recorded.
- Completion: The completed photomask is placed in the dry box in cleanroom bay M. Researcher is notified electronically of completion.
Alignment mark examples: