I remember a number 15nm as the average roughness for the limit but I might
be wrong. I am sure you can google it and find enough resources about it.
Also if you are using Pyrex from wafer companies like university wafer or
any other company they usually stock only polished Pyrex wafers.

Mehmet

On Tue, Apr 28, 2009 at 1:29 PM, Robert MacDonald <
robm@shearwaterscientific.com> wrote:

> Does anyone have standard specifications for pyrex wafer surface finish to
> achieve a good hermetic anodic bond to Si (assuming good conditions).
>
> In particular, I'm looking for a scratch and dig spec, or a surface
> roughness specification.
>
> Thanks,
>
> Rob MacDonald

--
Mehmet Aykol
University of Southern California
EE - Electrophysics
Phone: (213) 821-4090