Oray,
     Any barrel etcher has a lower etch rate than a parallel plate or microwave
etcher.  We used to rely on the fact we could load them with 50 or more wafers
and the resulting 30 minutes or more to strip resist could be considered better
than 1 wafer per minute.  The problem has always been that the energy is put in
by a coil wrapped around the barrel and the energy is distributed radially.  In
short the edges get twice as much stripping as the center and the uniformity
across a wafer is terrible.  The Oxford guy has the right idea.  Parallel plate,
low power, gas mix with low level Oxygen and high level inert gas.  We have had
excellent success with this approach especially as our power supply can be
programmed to give a steadily decreasing power output.  Think 200 watts to start
the reaction tapering off to 50 Watts at the finish.  let me know if I can help
in any way.  Bill Moffat

-----Original Message-----
From: Oray Orkun Cellek [mailto:[email protected]]
Sent: Friday, January 10, 2003 2:22 AM
To: General MEMS discussion
Subject: Re: [mems-talk] photoresist (Shipley series) thinning using low
rateoxygen plasmaRIE


Dear Mems-Talk Users,

I have another question related to the plasma-etch thinning of Shipley PR.

A Bio-Rad Barrel etcher, working at 150W 200mbar O2 plasma, etches
photoresist much much slower than 35nm/min order (the value which
Dr.Williams mentioned for parallel plate 50W) !

No problem about PR bake, chamber-contamination and others ...

Is such a slow etch rate a problem of barrel etchers or, is there another
problem?

Thank you for your help.

Oray Orkun Cellek
[email protected]
Research Assistant, Ph. D. Student
Electrical & Electronics Engineering Department
Middle East Technical University
06531 Ankara
Turkey
Tel : +90 312 210 4579
Fax : +90 312 210 1261

----- Original Message -----
From: 
To: ; 
Sent: Thursday, January 09, 2003 7:40 PM
Subject: RE: [mems-talk] photoresist (Shipley series) thinning using low
rate oxygen plasmaRIE


> > -----Original Message-----
> > From: Wei Wei [mailto:[email protected]]
> > Sent: Wednesday, January 08, 2003 3:31 PM
> > To: [email protected]
> > Subject: [mems-talk] photoresist (Shipley series) thinning using low
> > rate oxygen plasmaRIE
> > I try to use low oxygen plasma to thin my photoresist layer.
> > If anybody
> > have experience on this? Can you provide a receipe to control the
> > etching rate under 100nm/min?
> > Thanks,
> > Alex
>
> Just reduce the plasma power to slow the etch rate.
> As an example in a Technics PEII-A parallel-plate plasma etcher,
> with oxygen at 300 mTorr,
> at 400 W photoresist etches at about 350 nm/min;
> at  50 W photoresist etches at about  35 nm/min.
>
> --Kirt Williams Agilent Technologies
>
> _______________________________________________
> [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.memsnet.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.memsnet.org/