Charles,
Were the aligner microscope objective effective?, What wavelength IR was yr
camera sensitive to?

Thanks,
Shay
Charles Ellis wrote:

> Eric,
>
> One trick, we used a long time ago - was to add an IR camera to the
> trinocular, and use the light from the tungsten lamps (which includes enough
> IR) to see the backside.  This can be done on a standard aligner ( we did it
> on a old Kasper/Quintel Contact printer ). The IR from the tungsten lamps
> will reflect off the bottom chuck, and the reflected light will be visible
> in the IR camera. This of course assumes you are using silicon without IR
> blocking metals or other layers on the surface. We were able to perform very
> tight alignments (~1-2 um) with this technique.  The IR Cameras are a little
> expensive, but if you look hard you can find them slightly used.  We did
> have to have a special trinocular coupling made.
>
> This is the cheap way to do it, but it worked great.
>
> Good Luck,
> Charles Ellis...
>
> ----- Original Message -----
> From: "Eric Johnson" 
> To: 
> Sent: Tuesday, February 19, 2002 9:45 AM
> Subject: Re: [mems-talk] Is there a way to align two sides of wafer
>
> > You can do this with front to back through wafer alignment.  Karl Suss and
> > Quintel have front to back options for most of their aligners.
> >
> > Eric G. Johnson, PhD
> > Assistant Professor of Optics
> > School of Optics/CREOL
> > University of Central Florida
> > P.O. Box 162700
> > 4000 Central Florida Blvd
> > Orlando, FL 32816-2700
> > (407)823-6803
> > Fax 823-6880
> >
> > >>> [email protected] 2/19/2002 9:32:36 AM >>>
> > Dear Mems group,
> >
> > I have a single side mask aligner.  Is there a method by which this
> aligner
> > can be used to align features on both sides of the wafer?
> >
> > Thanks for your assistance.
> >
> > Marty
> >
> > Martin O. Patton
> > Senior Research Engineer
> > Essential Research Incorporated
> > 6410 Eastland Road
> > Cleveland, Ohio 44142
> > www.er.com
> > (440) 816-9850
> > _______________________________________________
> > [email protected] mailing list: to unsubscribe or change your list
> > options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
> > Hosted by the MEMS Exchange, providers of MEMS processing services.
> > Visit us at http://www.mems-exchange.org/
> > _______________________________________________
> > [email protected] mailing list: to unsubscribe or change your list
> > options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
> > Hosted by the MEMS Exchange, providers of MEMS processing services.
> > Visit us at http://www.mems-exchange.org/
> _______________________________________________
> [email protected] mailing list: to unsubscribe or change your list
> options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
> Hosted by the MEMS Exchange, providers of MEMS processing services.
> Visit us at http://www.mems-exchange.org/