Photoresists & Specialty Chemicals
C-MEMS & C-NEMS: 3D Carbon Microfabrication
Part of the Applications Notes Line
C-MEMS—in which patterned photoresist is pyrolyzed in an inert environment at high temperature—constitutes a powerful approach to building 3D carbon microelectrode arrays for 3D micro battery applications. High aspect ratio carbon posts are achieved by pyrolyzing SU-8 negative photoresist in a simple one step process.
C-MEMS technology is useful for 3D microarray due to C having attractive properties. These include mechanical durability, electrical conductivity, and chemical stability. High aspect ratio with low cost is obtained by using SU-8 with conventional photolithography followed by pyrolysis.
SU-8: Benefits/Attributes
- High aspect ratio
- Near vertical sidewalls
- >200 µm in a single spin coat
- No popping or voids created in resist structures after exposure
- Conductivity after pyrolysis of 1000°C for 1 hour, the SU-8 is similar to glassy carbon
Pyrolysis Chamber
Pyrolysis of SU-8
SU-8 posts
Pyrolized SU-8 posts
3D C-MEMS posts
3D C-MEMS posts
1. Coat and bake SU-8 2100
2. The SU-8 layer is exposed.
3. The SU-8 layer is post exposure baked.
4. Development
5. Pyrolysis
6. Carbon structures
SEM images and C-MEMS process courtesy of Chunlei Want@FIU and Marc Madou@UCI