Lift-off Process for High Density Metal
Electrodes(5-10 microns separation)
Roger Shile
2007-08-22
With these dimensions the LOR/S1813 system should work well. I had =
difficulty doing image reversal with AZ5214 and never succeeded in =
getting reentrant sidewalls. With 5-10um between your electrodes, you =
can undercut the LOR layer by 1um which will result in easy liftoff even =
with metal >1um thick. Evaporate the metal at 10 =C5/sec maximum to =
avoid coating the sidewalls.
=20
Roger Shile
=20
Original Message:
Dear All,
I am designing a photomask for a high density metal =
electrodes.
They electrodes are 2 microns of width, 5 mm long and separated by 5~10
microns. I am planning for 200 nm of Ti/Au metal. The first question =
will be
should I use image reversal (AZ5214 using bright field mask) or bi-layer
photoresis (LOR+S1813 using dark field mask)? OR should I use completely
different photoresist? I found in the mems-talk archive that bi-layer
photoresist has some problem for high density electrodes. Any suggestion
will be highly appreciated. Thanks in advance.
Newaz