Hi Sebastian, why did you use AZ400K developer with 1:2 dilution? Normally it is used at 1:3 or 1:4 proportion. another way i would suggest is to agitate the developer. Megasonic bath would be a good one, if you are cautious about your patterns. Yingtao -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Sebastian Sosin - EWI Sent: 07 December 2009 16:01 To: mems-talk@memsnet.org Subject: [mems-talk] AZ9260 residue after development I have a process to create tall (40-50 microns) pillar of AZ9260. After development (AZ400k, 1:2 dilution), I notice a residual film present on the wafer. The film is not present in areas where EBR was done (with acetone). The film can be removed by using a fine brush in the developer bath. This method is not desired and the surface is not clean even if the visible part of the film is gone. Can someone suggest a treatment to remove this film and not damage the copper pattern I have on my wafer? Regards, Sebastian Soisn