HI Liu, Really appreciate your work and feedback. As I mentioned in previous mail, adding more developer will help. My experience is that SU-8 developer saturates with PR quickly or slow down the development rate soon. I guess that is why the SU8 manual suggests second bath. In fact I feel interesting why you are so serious about the amount and time the developer added. I used a 4” crystallizing dish container for 3” Si wafer with SU8-2025 1500-3000 rpm, of about 1cm deep developer solution. I also leave it there for 5 minutes, or even 10 minutes more. Does it really matter to limit the developer amount and also count the time so seriously? I am just curious : > Anyway, as long as you reach your goal and know the limiting factor, that would do for you and us. Thanks. ucla Zeta yul.fany@gmail.com wrote: >Happy New Year! > >I think it might be helpful to keep you guys posted about my testing. >Today, I used a larger container for SU8 developer ( I used to use a >4in glass petri-dish) and refresh developer after each use. The >fabrication process is the same as before. > >For now, it seems that using more developer might help. However, I >compared the difference between beaker and petri-dish about 2 months >ago, and at that time, there was no difference -- see bright edges in >both cases. > >Best, >Liu Yu >