GCA 6300 Mask Making Guidance
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WIP - needs corrections, copied ASML instructions
- Use commercial mask/reticle houses: Photronics, Toppan, Compugraphics, etc.
- Instruct vendor that this will be used on an ASML 5500/300 system with 4x reduction. They have all outer templates to make your mask match our system. You just provide them the data you want printed, at wafer-scale (1X), and they'll scale it up 4x and insert it into the template.
- Reduction is 4X, instruct the mask makers to scale your CAD data to 4X size, which will determine price. Scale your mask critical dimensions (CD) and tolerances from the product quotes accordingly.
- Masks must be Quartz, 6" x 6" x 0.25” thick.
- Layer-to-layer alignment marks are provided by a calibration mask in our system. No need to put alignment marks on your CAD file.
- Spacing between mask-plate fields : 1mm of Chrome between fields (at wafer scale) in order for the reticle masking blades to blank off unwanted areas.
- Field Sizes Available (at Wafer-Scale, 1x):
- The full field useable exposure area is limited to the intersection of a 31mm diameter circle and a rectangle of dimensions 22mm x 27mm. See the schematic below for an illustration. Schematic of lens/aperture illumination. Fit a rectangle within this field to get the aforementioned rectangular field sizes.
- For High Resolution 0.63 NA: 21mm in X, 21mm in Y
- For 0.4 to 0.57 NA: 22mm in X, 22mm in Y
- Other rectangular sizes available, that fit within the lens/aperture intersection:
- 21mm x 23mm (X width x Y height)
- 20mm x 24mm
- 19mm x 25mm
- 18mm x 25.5mm
- 17mm x 26mm
- 16mm x 26.5mm
- 15mm x 27mm
- In general, 250nm resolution will resolve over the entire field. Anything smaller than this may not resolve closer to the edges of the field where lens quality degrades, and will also have a smaller viable process window (tolerance of exposure/bake/develop parameters). A number of users have shot ~150nm features.
When submitting the photo mask order, the following notes apply:
- Although you will submit your CAD file at 1x wafer scale, the actual reticle is printed 4x larger. Make sure to choose your reticle grade accounting for this; eg. If I want to shoot 1.0µm lines, I should choose a photomask grade better/equal to 4.0µm.
- “GDS Level” is also knows as “layer number”
- Barcode text for the plate must be 12 characters or less. Avoid special characters, a-z/0-9 only. This text is what you type into the job program.
- “Min. Feature on Mask” refers to minimum clear or chrome feature, assuming features similar to lines/spaces.
- “Min. Contact” refers to features with aspect ratio close to 1:1, eg. Squares and circles. These have a separate spec due to the manufacturing process, so make sure to choose the appropriate grade of photomask with this in mind.
- Choose a Critcal Dimension “CD” similar to your most critical feature (scaled to the 4x reticle scale), so they will print & measure & guarantee test structures at that size.
- For UCSB purchases: you will need to submit your order in UCSB Procurement Gateway first (as a "Non-Catalogue Item"), with the cost estimate from our negotiated quote, so that you can get the Purchase Order (PO) Number (usually in the same day). Then submit the order form to the photomask vendor with this PO number entered on their order form.
- When programming your job at the tool, you can fill out this Spreadsheet using your CAD file before starting your job programming:
- ASML Reticle Programming Params - MyReticleBarCode v1.xlsx
- GDS CAD file for for the ASML on-wafer alignment marks: