Laser trimming of MEMS

Abstract:
Laser trimming of Micro Mirror Devices promises an increasing yield in microfabrication. Therefore the 3DMicromac AG and the Center for Microtechnologies (ZfM) have developed a module for measuring and tuning silicon micro actuators as well as microstructures. By using an ultra short pulsed laser with an UV-wavelength the cutting of previously etched mass trimming elements and beam stiffness trimming elements has been implemented. These elements for modifying the resonant frequency of the micro mirror device are cut off by removing of silicon connector bars. The resonant frequency was influenced successfully by using this laser trimming tool in a clean room environment at wafer level and the subsequent bonding process of the wafer was demonstrated.