Kirthi,
        I am in the process of mechanically drilling some holes for some
clients in glass 150um diameter. In the past I have mechanically made
holes, channels, and cylinders in Si as small as 80um. The advantage of
this method is that it makes nice clean holes, nice straight walls, without
melting surrounding material.
        If you like, I can send you a sample of the glass holes and
pictures of the silicon holes and channels next week if you send me your
mailing address.
        John Klemic
        626-395-2281

>Dear MEMS enthusiasts,
>
>Has anyone laser drilled holes on a 50-100
>micrometer thick silicon membrane, to get a roughly
>cylindrical cavity. I need holes of diameter of
>about 50 micrometers on a Silicon membrane of the
>above mentioned thickness. If anyone knows of any
>publications in this area or can offer any advice or
>tips, I would much appreciate if you could send them
>to me.
>
>Thanks in advance,
>
>Kirthi Roberts
>
>--
>__________________________________
>Kirthi Roberts
>School of Engineering Science
>Simon Fraser University
>Vancouver,
>Canada
>e-mail : kroberts@sfu.ca
>