Hi Adnan,

Thank you for your advice. I'll try it out.
brgds,
Nang Htoi

adnan merhaba  wrote:
hi

The copper might be contaminated/oxidized from prior
processing. Try dipping your wafer for 30 seconds in
10% Sulfuric Acid prior to etching. It will greatly
increase your etching uniformity.

regards,
adnan merhaba


--- Lahpai Nang Htoi wrote:
> Hi,
>
> I have an issue with Cu UBM wet-etching. I use
> Nitric acid together with acetic acid and hydrogen
> peroxide. Although my over etching time is long
> enough (50 to 80%) to clear all un-masked Cu, round
> shape Cu residue is left behind.
> Does anyone know what causes this kind of residue?
> Any idea or suggestion will be greatly appreciated.
>
> Thanks & brgds,
> Nang Htoi
>
>
> ---------------------------------
> Do you Yahoo!?
> Win a $20,000 Career Makeover at Yahoo! HotJobs
> _______________________________________________
> MEMS-talk@memsnet.org 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/





__________________________________
Do you Yahoo!?
Win a $20,000 Career Makeover at Yahoo! HotJobs
http://hotjobs.sweepstakes.yahoo.com/careermakeover

_______________________________________________
MEMS-talk@memsnet.org 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/

---------------------------------
Do you Yahoo!?
Win a $20,000 Career Makeover at Yahoo! HotJobs