Determining the physical properties of EpoClad negative photoresist for use in MEMS applications

In this paper, the internal stress and Young modulus of EpoClad are investigated using different methods. The swelling behavior when submerged in common processing liquids is also measured and reported. Different on-wafer micro electromechanical structures are used, together with nanoindentation measurements. The experimental results yield an internal stress that is strongly dependent on the processing conditions, the ambient and the submersion liquid. Young's modulus is found to be 4.4 ± 0.2 GPa