Cantilevers became popular with the invention of the atomic force microscope (AFM) in 1986. Micro cantilevers are used in microcalorimetry, mass detection with resonating devices, and magnetic force microscopy. As an example, in biosensing, changes of surface stress or the selective attachment of various molecules induce static bending of the cantilever. The simple mechanical behavior of cantilever-based sensors allows straightforward translation of mechanical forces into displacement. Various applications of SU-8 cantilevers with the thicknesses of 2 10 µm have been described in the literature.
Highly chemical resistant
Low Young’s Modulus
Relatively easy fabrication
Surface can be modified
PMGI Material Attributes/Properties
Spin-coatable from 10nm to 6nm in a single coat
No intermixing with imaging resist
High thermal stability <300 C (Tg~189C)
Strippable in NMP and aqueous-based developers
Resistant to conventional semiconductor solvents
Excellent adhesion to various substrates
DUV, E-beam and x-ray sensitive
High etch rate in O2 plasma
Excellent conformal or planarizing formulations available
1. Coat release layer according to supplier recommendations.
2. Coat SU-8 layer according to the datasheet recommendations.
3. Expose and PEB SU-8 layer. Do not develop.
4. Coat second SU-8 layer according to datasheet recommendations.
5. Expose and PEB second SU-8 layer.
6. Develop SU-8 layers.
7. Release SU-8 layers from the substrate.
Journal of Micromech. Microeng. 21, 2011 M. Suter et al. SEM image of a micro cantilever made of a magnetic photo curable polymer SU-8 composite with 5 vol.% Fe3O4 particle content. The cantilever has a length of 80 μm, a thickness of 1.8 μm and a width of 14 μm.