I have used the third one, which is the Aqua Regia and
it is good for photoresist, oxide, nitride mask. It
does eat Al and does not attack Cr. The water in the
solution is 50% by volume, so if you have 80 ml of the
HCl and the nitric acid (total) then add 80 ml of DI
water.I would certainly recommend Aqua Regia only if
you do have masked the Al with resist.
Hope that helps
Rohit
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On
Behalf Of Roger Shile
Sent: Monday, February 11, 2002 2:24 PM
To: [email protected]
Subject: Re: [mems-talk] wet etching of Au
I use Transene TFA Gold etchant, which is a solution
of iodine and potassium
iodide. I don't believe it will significantly attack
any of the other
materials you mentioned.
Roger Shile
>>> [email protected] 02/11/02 01:31AM >>>
I have to etch Au layers of different thicknesses
ranging from 100 nm to 2
um.
I found different chemicals to etch gold: (1) KI:I2:DI
H20=4:1:40
(weight), (2) HCL:HNO3:DI=4:4:9 (volume), (3)
HCL:HNO3:DI H20=3:1:?
("king's water")
Does anybody know about the selectivitiies of such
etchants to Al
(!!), SiO2, SiN, Cr, Si. Do you have experiences with
these etchants
regarding uniformity, etching rates, selectivity,
suitable mask
materials? Which one could you recommend?
Thanks a lot for your answer(s).
--
-----------------------------------------------------------------------------
-
Joachim Oberhammer, Dipl.-Ing.
Royal Institute of Technology (KTH) Phone:
+46/(0)8 790 6250
Dep. of Signals, Sensors and Systems Fax:
+46/(0)8 10 0858
Microsystem Technology (MST) Mobile:
+46/(0)70 692 1858
e-mail:
[email protected]
Osquldas vdg 10 homepage:
http://www.s3.kth.se/mst/
SE-100 44 Stockholm, Sweden
_______________________________________________
[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/
Send FREE Valentine eCards with Yahoo! Greetings!
http://greetings.yahoo.com
