Investigations of surface properties of SiO2 and Si3N4 thin layers, used for MEMS vibrating structures applications

To understand the surface topography of MEMS vibrating structures, different effects as contact phenomena, stiction, friction, adhesion, etc, on the lifetime and performance of these devices, require special consideration. We obtained results regarding the topographic analyses of 3 different experimental samples, using the same design, but different materials for manufacturing, specific to MEMS technology. Three different test methods were performed on three separate types of samples. The samples were fabricated as following: Silicon, Silicon Oxide layer on Silicon and Silicon Nitride layer on a Silicon Oxide layer on Silicon. In order to measure their properties a topography scan, a comparative friction test and a pull off-force measurement were carried out using an Atomic Force Microscope (AFM).