Design and analysis of polysilicon thin layers and MEMS vibrating structures

Natural frequencies of an array of microcantilevers designed with different dimensions were analysed using computer simulations. Four different types of polysilicon were obtained in different processing conditions varying the deposition temperatures (580°C, 610°C, 630°C, 650°C). A topography scan, a comparative friction test and adhesive tests (pull off-force measurement) were carried out using Atomic Force Microscope (AFM) in order to characterize the material properties. Mechanical properties such as hardness and Young´s modulus have been investigated using the nanoindenter technique. The microcantilevers have been manufactured using polysilicon as structural material and surface micromachining technique.