Hi,

I have 1-um-thick, 100um-by-100um square SU8 posts, and I want to fill
around them with a sacrificial layer preferably photoresist.  When I spin
coat the photoresist (approximately 1-um-thick), and develop away the resist
over the posts, raised lips appear at the edges of the posts.  I tried
oxygen plasma to planarize the surface to some degree while depositing
multiple photoresist layers to reduce the lip formation, but it doesn't work
too well.

Is anybody aware of a surface planarization technique that doesn't require
CMP?

Thank you.

erkin