Stress Relaxation of Polyimide (PI) Cantilevers using Low Energy Ion Bombardment

Released structures such as polymer cantilevers can experience a form of residual stress induced bending that is often undesirable for MEMS applications. We present an approach to eliminate stress induced curvature in Polyimide (PI) cantilevers by low energy ion bombardment in plasma. White light interferometry, SEM and X-ray photoelectron spectroscopy (XPS) have been used to investigate the deflection and surface modification of PI cantilever after exposure to Ar+. We show that it is possible to control and fabricate stress free PI cantilevers by optimizing ion bombardment parameters.