Large deflection micromechanical scanning mirrors for linear scans and pattern generation

An electrostatically driven silicon micro scanning mirror (MSM) for one-dim ensional (1-D) and two-dimensional (2-D) deflection of fight is presented. A special configuration of the driving electrodes allows the use of small e lectrode gaps without restricting the deflection of the plate geometrically , In this paper, the starting of the oscillation and the operation of the s canner is discussed. Experimental results show that scan angles of up to 60 degrees can be achieved at a driving voltage of only 20 V, The 2-D deflect ion of a laser beam is obtained by a gimbal mounting of the mirror plate. F or the fabrication of the devices, SOI-wafers are used as the base material , The mechanical structures are defined by a deep silicon etch, For the ele ctrical isolation of areas on the movable frame, polysilicon-filled trenche s are used. The mechanical stability of the scanners is tested. The devices resist shocks of more than 1000 g and show no change of the resonance freq uency even after long run tests of 7 x 10(9) periods.