Andy,

Eddy is looking for a maskaligner, a lithography tool doing full field wafer
exposures. BSA (back side alignment) is a technology to align the mask to
the wafer by using reference marks which are located on the back side of the
wafer. BSA  is necessary for applications where both sides of the wafer are
to be patterned or where the standard alignment procedure from the top side
is not possible for certain reasons. Earlier solutions to align targets on
the back side of the wafer to the photomask used IR-light to look through
the wafer. However, certain substrates such as metallized wafers do not
allow IR alignment and therefore require the BSA technology, where the
alignment microscope is positioned under the wafer and thus directly looking
onto the back side. The challenge with BSA is the fact that the fiducals of
the wafer and the mask cannot be seen at the same time (as it is the case
with standard top side alignment) because the wafer is hiding the mask when
in alignment position.

Maskaligners with BSA capability for manual alignment as well as for fully
automated alignment are available from SUSS MicroTec. Please visit our web
page at http://www.suss.com or contact me directly if you are interested in
further details.

Best Regards,

Frank.

--------------------------------------------
SUSS MicroTec
Applications Center Europe
Frank Runkel
Schleissheimer Str. 90
85748 Garching
Germany
Fon     +49 89 32007 - 302
Fax     +49 89 32007 - 390
email   [email protected]



> ------------------------------
>
> Message: 9
> Date: Mon, 14 Apr 2003 10:12:22 -0700
> From: Andy Rossi 
> Subject: [mems-talk] double side aligner, WykoNT3300 (MEMS Eng.)
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> Can you please explain what is meant by "backside aligning capability"?
> Do
> you mean OCR and/or barcode reader on the backside?  Most aligners I'm
> familiar with (including ours) align on the silhouette of the wafer;
> neither the backside nor topside.
>
> I have a lot of experience in wafer automation...if I understand the issue
>
> I may be able to point you in the right direction.
>
> Thanks,
> Andy Rossi
> Director of Sales and Marketing
> North America
> Coreflow Scientific Solutions
> Phone: 408-353-4306
> Fax: 408-353-3124
> Mobile: 408-655-6514
>
>
>
>
>