Hi everyone,

I am using SPR 220-7 photoresist and am looking at 7 micron thickness. I am
spinning at 3500 rpm for 30 seconds and also tried 3k rpm for 30 seconds.

I see a lot of streaks on the wafer and not getting a uniform coating. I did
take a look at Stanford nanofab website (www.snf.edu) but the problem is that I
have manual spinners and their manual procedure is also not working fine for me.

If anyone has worked with it before, your suggestions would be invaluable.

Thanks in advance.
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