We use liftoff process for our chip patterning. The metallization metal is
either gold or copper. We use same lithography process for both gold
patterning and copper patterning. However, I notice that copper always shows
a very clean gap after liftoff while gold always have residue on the edge of
the gap. Can somebody explain why? Your help is very appreciated!

Jessie Zhang
Sr. Thin Film Engineer
Paratek Microwave, Inc.
[email protected]
443-259-0140x153 (O)