[mems-talk] Su 8 thickness

[Oakes Garrett]

Try using more resist and slowing down the spin speed.  Alternatively, use a double coat process.  I have had much success with a double coat process to 500 µm using SU-8 2100.

Best Regards,
Garrett Oakes

EV Group 
invent * innovate * implement
Regional Sales Manager North America - Direct: +1 (480) 305 2443, Main: +1 (480) 305 2400 Fax: +1 (480) 305 2401
Cell: +1 (480) 516 6724
E-Mail: G.Oakes at EVGroup.com, Web: www.EVGroup.com
 
-----Original Message-----
From: jiang Liudi [mailto:ldjiang at hotmail.com] 
Sent: Wednesday, August 06, 2008 5:51 AM
To: mems-talk at memsnet.org
Subject: [mems-talk] Su 8 thickness

Dear all,
 
I was trying to obtain >100um thick of patterned SU8 2075. The used receipe is as follows:
 
spin: 500rpm/10s+1700rpm/30sec
soft bake: 65 C/5 mins +95 C/20min
UV expose: 28 sec. 
PEB: 65 C/5 mins +95 C/10 min
develop: 10 mins. 
 
all designed patterns are large ( all around 50-200um). However, using profiler, the  step of the developed patterns is only about 66 um thick. 
 
Could anyone kindly suggest the possible reasons for such thin resist?
 
Many thanks. 
Jiang