Hi You can go for the BOSCH DRIE process.... provides very high aspect ratio... not sure...consult...and let me know... On Tuesday, 6 May 2014 9:23 PM, Antoine Blinwrote: Hi everyone, I am using standard techniques for fabricating SU8 mould for microfluidic PDMS devices, but i am having troubles obtaining a correct aspect ratio. Does anyone have some tips to achieve a: - 50 µm height - 10 µm width pattern - a 0 - 3 µm variation in width of the pattern between substrate and the top. The resolution of the mask (SELBA, Switzerland) is checked and good, I am working in hard contact, and use a 365 nm i-line filter for the exposure. I may think this is related to diffraction, would you suggest to use: - under exposure? - flash exposure? - other ideas?? I also tried multi layers to minimize the diffraction effect on each step, but the pattern is particulary difficult to align (big area and small parallel patterns..) Thank you for your help! Antoine Blin _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk