Dear Researcher,

I am still a beginner in fabrication, and I have these following problems in the
lift-off process. In order to provide the context, let me briefly write the
process steps:

1) PMMA film (200nm thickness) is patterned using Electron  Beam Lithography
(developed for 60s and IPA for 30s).
2) Patterned PMMA film was subjected to UV Ozone Stripper (SAMCO UV-1) for 60s.
3) The sample was deposited by Ti with 20nm thickness (with the rate of
0.06nm/s)
4) The sample was soaked in Acetone.

Problems:
1) There are cracks everywhere in PMMA film after E-Beam Evaporation.
2) The PMMA cannot be removed by acetone.

Any help would be very much appreciated.

Best Regards,

Lando