Agung Shamsuddin wrote:

>Dear friends,
>
>I have applied SU-8 layer with thickness around 500 micron on glass.
>
>I thougth more longer softbake process will remove more solvent.
>All the softbake procedure give me flat, smooth and dry (no stick on mask
>when exposure) SU-8 layer
>
>and then i exposed  by using recomended exposure dose from manufacturer
>datasheet.
>
>but all the procedure always give me wavy surface of SU8 layer in result.
>
>Please, any opinion and suggestion welcomed.

Hi

I have also experienced similar problems.
Although I haven't fully solved it I believe it is caused by the lower
portion of the SU-8 layer not being fully cross-linked.
This could be due to deep UV (<360nm)  preferentially exposing the top
portion and/or under exposure.
You could try increasing the exposure dose to ensure total crosslinking
throughout the layer and/or filtering out the UV below 360nm.
Please let me know if this works (I haven't yet had time to fully
investigate it myself).
Best regards

Gareth