[mems-talk] Stiction problems in SU-8 cantilever

[Maria Nordström]

Dear Jeffrrey, 

My experience is that if the SU-8 cantilever is very thin (say 1.5 µm) then the cantilevers will stick to the substrate even with a spacing of several microns. However, making a 4.5 µm thick cantilever will prevent the stiction. I wouldn't say it's the hydrophobic/hydrophilic properties of the material that has the biggest effect but rather the capillary forces since you use a wet release method.   

My advice would be to move to a dry release, as for example the method developed by D. Haefliger; D.Haefliger et al. Microelectronic Engineering, 78-79 (2005) 88-92.

Good luck!
Maria 

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Maria Nordström 
PostDoc, Nanoprobes Group
MIC - Department of Micro and Nanotechnology
Technical University of Denmark
Denmark