Simulation and experiments of intrinsic bending of multilayer microcantilever for maskless scanning plasma etching

In the maskless scanning plasma etching system proposed by our group, the microcantilever probe integrated with microdischarge device is a Ni-Polyimide-Ni-SiO₂-Ni multilayer structure. The intrinsic stress in multilayer thin film is important for it may cause undesirable bending deformation of the cantilever. In this paper, we experimentally measure and calculate the internal stress of thin films of the cantilever based on classical Stoney formula. Simulate result of cantilever deformation shows that the compressive and tensile stress of multilayer film could be almost balanced. A relatively straight microcantilever intergated with microdischarge device is successfully microfabricated with good quality. The results of this paper may lay a foundation for further scanning plasma maskless etching.