I don't know what surface you had on before the Ti, but adhesion layers work
best if they are prepared in-situ.

In other words, try first putting down the PMMA, then put down the Ti and
the Nickel during the same pumpdown.

David Nemeth

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of madhav rao
Sent: Friday, May 11, 2007 8:31 PM
To: [email protected]
Subject: [mems-talk] Adhesion layer for Nickel during Liftoff process

Hi All,
       I had sputtered Titanium layer. then I did spin
oat of PMMA. After exposing it (E-beam lithography),
Nickel was deposited using E-beam evaporation. Finally
Liftoff was carried out to remove PMMA. However after
liftoff, I could not see any Nickel and Titanium.
Please let me know, which is the better adhesive metal
for Nickel in Liftoff process.