Changsoon

Sounds like a spitting problem.  Without knowing the whole story of how you
are doing your deposition it is hard to answer, but here are a few quick
suggestions.
- Lower your dep rate, slower rates take less power to deposit and usually
result in less spitting.
- How clean is your gold?  A film can sometimes be visible on the surface
during dep which could be due to carbon contaminating the gold.  This always
happens and could affect your dep if it is bad.  A way around this is to
stick a small piece of tantalum in your gold, just take a small piece of Ta
wire and coil it in the bottom of your gold.  I'm not sure of the chemistry
but it does react somehow with the carbon.  I think 1" should last several
runs and then you might want to add more if the film gets bad.  It shouldn't
affect your films at all.

Good luck
Rick Williston

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Changsoon Kim
Sent: Wednesday, February 12, 2003 10:30 PM
To: [email protected]
Subject: [mems-talk] Spherical lumps of Au for E-beam evaporated film


Hi all,

Au films that I deposited using an E-beam evaporator
have some spherical lumps of Au on the surface.
The radius of the spheres are 200 nm ~ 2 um, and
the samples are Si/2.5nm Cr/5nm Au.

Can some of you let me know why this happens and
how I can avoid it?

Thanks,

Changsoon Kim

Dept. of Electrical Engineering
Princeton University


_______________________________________________
[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/