Investigation of SU8 as a structural material for fabricating passive millimeter-wave and terahertz components

This paper provides a systematic review of the technical issues of SU8 fabrication for millimeter-wave and terahertz components based on research carried out at the University of Birmingham in the past decade. A design-for-manufacturability approach is followed. The flexibility of the SU8 process enables many device structures. Challenges and problems during fabrication will be discussed and demonstrated with examples. The measurement of the devices is also a significant challenge when the critical dimensions of the device shrink and special testing fixtures are needed in some cases. Finally, a brief overview of the issues discussed above is given for future guidance.