Design, microfabrication and analysis of polysilicon thin layers for 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, 610, 630, 650 °C) for the same thickness of 2 μm. A topography scan measurements were carried out using atomic force microscope in order to characterize the material properties. Mechanical properties such as Young’s modulus have been investigated using the nanoindenter technique. The microcantilevers have been manufactured using surface micromachining technique with the structural material undoped and doped polysilicon.