I made a SU8 2075 molds with Mylar mask. My problem is that all diagonal
features are peeled off after 5-6 minutes in SU8 developer, while almost of
all vertical and horizontal lines or dots are still firmly attached on the
silicon wafer. Here are main steps of the protocol: clean Si wafer with BOE,
spin coat SU8, soft bake, UV exposure, PEB and then SU8 developer. The
diagonal features are 5 -10 um (width) x 80 um (height), the other features
are 40 um or up. By the way, this is my first time to use Mylar mask for
making SU8 2075 molds. I had no problem of using the similar protocol with
glass/Cr masks for making other SU8 molds.

Could somebody assist me with his/her own experience or suggest a reference?

Wang