17-06-2010, 12:47 PM
Presented By:
S.G. Lokhre, K. Virwanif , B. Gajananf , S.P. Pai, P.R. Apte
Solid State Electronics Department
Tata Institute of Fundamental Research
Homi Bhabha Road
Colaba, BOMBAY - 400 005, India
ABSTRACT
We have designed, fabricated and tested a balanced doubly suspended versatile, torsion and flexural, MEMS resonator structure. The doubly suspended structure has been used earlier for very precise high Q resonators but we wished to study the various vibration modes of such a structure. FEM analysis has been used to compute the most likely 6 modes and their frequencies of free vibration. These modes include flexure, torsion and mixed modes. The arms of the resonator are deposited with magnetic films so as to give desired bending/twisting moments to the structure. The location of the films decides the symmetry and thus result in one of the six vibrational modes that are predicted by the FEM analysis. This paper describes the design, fabrication and measurements on resonator structures made at TIFR.
Introduction
Traditionally silicon has been the bane of transistor and integrated circuit (IC). It paved on the way to very large scale integrated circuits (VLSI) wherein the device structures were of the order of few microns. Apart from this phenomenal success in the field of microelectronics, silicon has now provided the micro-electromechanical-systems (MEMS) wherein micron sized structures are fabricated in single crystals of silicon as mechanical sensing devices.
These microstructures made of SiO2 having dimensions 1-10 micron in width and 50-100 micron in length were suspended over a 100 micron deep cavity in silicon. The 100 micron X 100 micron square cavity was obtained by a crystallographic etchant KOH. Such microstructures then bend or vibrate in the cavity formed giving a 3D like effect to the devices. Some of the microstructures fabricated in our laboratory 1 are as follows namely Cantilevers, Cross-bridges, Spirals, Doubly suspended resonators, Micro-probes, Magnetic sensors etc. These microstructures were subjected to different treatments for different applications, like evaporation of metals for thermal applications or sputtered with magnetic materials for magnetic actuator like applications etc.
read full report
http://ee.iitb.ac~apte/CV_PRA_MEMS_PAP2.htm
