Hello all,
I am currently using a 7"x7" photomask for my work.I had procurred the
Photomask blank  (Cr blank) from a company called as Telic in USA.
To clean the photomask I use 70% Sulphuric Acid +30% Hydrogen Peroxide
(Pirana solution). I dip my photomask in this solution for 7 minutes and
then clean in thoroughly in DI water.
Can anyone suggest whether the procedure is correct and do I have to
something else to clean the mask. After Cleaning the photomask, the Cr side
looks pretty much clean, but the glass side of the photomask still has
stains/spots. I suspect that the stains/spots are not on the glass side, but
inside the glass and hence I would like to ask whether anyone has experience
in using photomask blanks from Telic.
Regards,
Sudesh

Dr. Sudesh S Bhagwat,
Samtel Centre for Display Technologies,
Indian Institute of Technology Kanpur,
Kanpur - 208016. INDIA
Tel:+91-(0)512-2596088
Fax:+91-(0)512-2596089