Maskmaking
Services:
- Some Commercial service providers recommended by SNF labmembers are listed here.
- Special Academic Pricing is available to SNF academic labmembers (SUNet ID required.) Non-Stanford academics are also eligible
for academic pricing and may contact Staff for information.
- ASML Masks have special requirements:
- Only mask suppliers
approved by the ASML engineering staff at SNF may be used for fabricating
masks to be used on the ASML system here. Currently, only Compugraphics
and Benchmark are approved as suppliers.
- Modified masks
(including adhered films or materials, cut-down plates) may not be used
on the ASML system at SNF without prior approval from the ASML engineering
staff.
- Transparency
Films :
For an inexpensive alternative, a mylar
transparency print from a high-resolution photo-quality copier (also
called "film plotting") can be used as a contact mask in place
of a standard photolithography mask. Transparency films don't wear well
and have limited feature size resolution (depending on the print quality),
but they are cost-effective for limited patterning of larger structures.
A caveat: conventional laser printers do not print densely enough for
to sufficiently block UV illumination; only film plotters with print density
of at least 3800 dpi will work. Go <here> for a list of film plotter providers.
Getting
Started: First,
you'll need to layout your design. Some good references are listed below.
Laying out
your device:
The recommended file format for quality mask layouts
is GDSII. Layouts can be done in AutoCAD or other programs which output
to DXF, but be aware that there are common problems and extra costs often
associated when submitting files to maskmaking services using DXF formats
(see Photomask Basics). SNF recommends using Tanner LEdit (though
other GDSII layout programs are often used too) because it is flexible,
yet robust. The CAD room, across from the Gowning Room, houses two dedicated
desktop CAD PC's which are loaded with Tanner LEdit. The left-side PC
also contains several nifty utilities which allow file conversion between
DXF (for die-hard AutoCAD users), GDSII, and PostScript (for printer later
or for creating Transparency Masks). These are
available for anyone to use; instructions and guidelines for their use
are posted above each system. SNF also has several Tanner LEdit portable
license keys, which Stanford researchers can check out. Contact Staff
for more info.
When using
LEdit, make sure to review the "Tips and Tricks
for using LEdit" section. This page lists the optimal program
settings and ways to get the most from your layout with minimal cost and
confusion. If you have comments and suggestions to add to this or any
other page, contact staff.
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