June 17, 1995

Due to the recent flurry of interest in mask making, I thought I would point
out that my company has developed a completely different technology for making
high resolution, continuous-tone, gray-scale masks. We use this technology
internally for making gray-scale, analog optical memory chips for optical
pattern recognition systems, and have used it in a limited fashion for making
optical devices using reactive in etching.

We can achieve a spatial resolution of 1 um over a large field. We can provide
a different shade of gray for each 1 um pixel. This is a very high quality,
e-beam and thin-film deposition process, which is expensive to practice --
several thousand dollars and up per mask. We can provide many shades of gray
over a dynamic range of 50:1 or more -- depending upon how many steps are used
in the mask-making process. We have developed a simple, bit-mapped interface to
our software; we accept PC-standard, bit-mapped files such as the PCX format.

I would like to hear from people who have used gray-scale masks for optical or
MEMS processing, or who have need of it.

Regards,

Steven G. Morton, President
Oxford Computer, Inc.
39 Old Good Hill Road
Oxford, CT 06478
tel 203-881-0891, fax 203-888-1146, e-mail: [email protected]