The GCA Mann 3600 pattern generator is designed for patterning standard 5" x 5" mask plates for use in optical lithography. Pattern designs are created in AutoCAD. The AutoCAD file is then converted into binary format, which can be fractured into data read by the pattern generator. The illumination source for exposures is a high pressure Hg arc lamp. The light is filtered and projected onto a shutter, which controls the exposure dose. A set of aperture blades (vertical and horizontal) can be rotated from 0 to 90 degrees to create retangular images of varying sizes and orientations to form the pattern design. A focusing column images the apertures onto the mask plate. The mask plate is secured onto a fine motion stage, which positions the plate at each exposure location.
After nearly 6 months of down-time, the OPG is now available for use. Users should be aware that there is an error in the width aperture setting (see example below) until further notice. Users are encourage to compensate for this error in their design and to send their drawing file to Staff for verification.