Resonance Frequency Trimming for MEMS Micro-Mirror Scanner

MEMS devices with harmonic oscillators resonating at specific frequency are useful in variety of applications. One of these applications that demands high and accurate resonant frequency is optical scanners for display applications. Due to the large tolerances of MEMS fabrication a calibration is required to achieve accuracy in resonance frequency. In this paper we present a novel technique for frequency trimming and spring stiffness trimming. The proposed technique is one time one direction frequency trimming and is based on anisotropic wet etching process, the same process used for fabrication of the device itself. We also present some preliminary results of resonant frequency of micro-mirror scanner devices for display applications before and after trimming process. Key-Words: MEMS, mirror, scanner, resonance, frequency, trimming, calibration, anisotropic, wet, display.