Ti is tough to thermally evaporate.  If you can get away with Cr (also a
good adhesion layer for gold), then something like this:

http://www.lesker.com/newweb/Deposition/Evaporation_Sources/Thermal_Rods.cfm

might work.  (There are other manufacturers besides Lesker).  I used these
all the time, with good results.

David Nemeth

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Yue Mun Pun, Jeffrey
Sent: Friday, March 02, 2007 12:57 AM
To: [email protected]
Subject: [mems-talk] Problems with evaporating Titanium

Hi,
In my process, I am trying to evaporate Titanium on uncrosslinked SU-8.  The
purposes for the Titanium are:
1. To serve as a masking layer to protect the underlying uncrosslinked SU-8
from further i-line UV patterning processes.  Thus, it has to be at least
25nm thick.
2. To serve as an adhesion layer for Gold, which will be e-beam evaporated
on the Titanium to a thickness of 200-300nm.

For Titanium as a masking layer, I am attempting to resistively or thermally
evaporate the Titanium to a thickness of 30-40nm.  However, this continues
to prove to be a challenge?  The evaporator I use is Edwards Auto 306
thermal evaporator.  I use Titanium granules of <2mm size and Titanium is
99.5% pure.

Can anyone advise me how to go about evaporating the Titanium or can I use
e-beam evaporation of Titanium on uncrosslinked SU-8 2050.  E-beam
evaporation is much easier, in my experience.  However, the only concern is
that e-beam might cause undesired crosslinking of the underlying SU-8 2050.