Heidelberg Mask Writer

Nanofabrication Facility


Heidelberg Inst.




Cleanroom G07 LISE

The Heidelberg DWL 66 is a high resolution, laser-based maskless optical lithography system, used at CNS for writing photomasks.

Detailed specifications include:
*Exposure laser: 405 nm diode
*Maximum resolution: 1 micron
*Maximum pattern extent: 140 x 140 mm
*4 inch and 5 inch soda-lime glass photomasks are stocked by CNS
*Accepts GDS format CAD files.


Masks can also be ordered from CNS staff, with added charge for CNS remote staff assistance along with the hourly rate for the maskwriting tool.

The necessary CAD file format for our mask writer is GDS format, produced by numerous software packages including LayoutEditor. All other CAD file formats will need to be converted to GDS format. DXF files can be converted to GDS format files via the program LinkCAD, available in the CNS basement computer lab. The CNS document SOP 123 explains how to perform this conversion.
CNS staff can perform the conversion from DXF to GDS format. Indicate the base unit used for the DXF drawing, make sure that all features are closed, and do not use the hatch option. Convert all text to polygons. Save files as compatible with Autocad 2000 or earlier. Note that staff conversion assistance is charged at the normal rate for assisted staff work, and is separate from any fees associated with the mask write itself.

In addition to the CAD file, the following information must be submitted with the mask order:

*minimum feature size

*whether enclosed features should be opaque or transparent

*size of the mask plate needed (the standard is 4 inch, soda-lime glass).

*For GDS files, include the name of the top level cell, and the numbers of the data layer(s) to be written on the mask.

*Convert all text objects and paths to polygons.

Objects left as text or as paths, even paths with defined width, will not be written by the system.

Writing time, and thus mask cost, is a function of the minimum feature size and the extent of the mask pattern.

Training on the maskwriter is offered weekly, and sign up is via the CNS training webpage.