Joe,
Have you looked into bonding with SU-8 or BCB? In both cases, these materials
can be spun on and bonded using relatively low temperature. You would then
follow up by a UV exposure through the glass to cross link the materials, at
which point they become highly chemical and heat resistant.
Another alternative may be direct anodic bonding, but that can depend on the
comparative thermal expansion of the two materials, and the make-up of the glass
(although glass slides will typically bond under potential).
Best Regards,
Chad Brubaker