UC Berkeley uses a Canon FPA-141F 4x mask aligner for small wafer
substrates and GaAs substrates. The Canon FPA-141F uses a round, precision
fused silica discs, anti-reflection coated as a planar image plane. These
discs are subject to damage and need to be replaced from time-to-time.
Canon will no longer supply this item. I have secured a quote from an
optics company for custom fabricated replacement discs. As is usual in
custom glass fabrication the more pieces we order the lower the cost.

If you have a Canon FPA aligner and are interested in sharing the cost of
custom fabrication of fused silica discs e-mail me. I will get back to
you with the particulars.

                                        Sincerely,
                                        Bob Hamilton

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