Hello Wei Ming En

I am not sure of the steps in your current process. Furethermore, what are your feature sizes? What are your post-exposure steps?

My first suggestions would be to include a dehydration bake before spincoating (e.g., 120-200 oC for 10-20 min), and/or to try surface activation by oxygen plasma (or UV-Ozone).

Jules

Dear Professor Jules Lloyd Hammond

Thank you for your reply and suggestions. I am sorry for ignoring the detail of my question.

The size of my feature is a rectangular 3cm*1cm

The substrate is PET and I sputtered Cr and ZnO on it.(figure1)

And then I spun photoresist on it.

Here is my parameter of photolithography.

First, rinsed with acetone, isopropyl alcohol, deionized water and blow-dried with nitrogen and then put it on 130⁰C hot plane 2 minutes to let them dry.

       1-spin: 500 rpm, 5 s

       2-spin: 3000 rpm, 30 s

       Soft bake: 125⁰C,3 min

       Expose: 200 s

       Develop: 1:4 (for about 30s)

       Hard bake: 125⁰C,2 min

I interested