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The Fraunhofer Institute for Silicon Technology in Itzehoe has developed vacuum encapsulated dual-axis scanning micro-mirrors, for high-resolution laser projections [1]. Sinceparallel orientation of the glass cover to the micro-mirror results in a bright laser spot in the projected image, a wafer level packaging with an inclined glass lid was developed to eliminate the reflex in the image. To determine the quality requirements and the design specifications of the new package, optical simulations were performed in Zemax®. For this purpose, the influence of the surface curvatures on the laser beam was examined. A further study was focused on the avoidance of secondary reflections, resulting in a disturbing ghost images superimposing the projected image.

This paper presents a new fabrication technology for conducting AFM cantilevers with integrated AlN-based piezoelectric actuators. A major effort has been done for the process integration of a high quality AlN layer onto the Si cantilever together with a high wear resistance, PtSi-based conducting tip. Functional AFM devices have been successfully tested in tapping mode imaging experiments. Such type of cantilevers are of great interest for dynamic AFM applications especially for tapping or dithering mode AFMs as well as for using the piezoelectric structures as an integrated position sensor.

A comprehensive study on the complete process module for the fabrication of AlN-based MEMS sensors and actuators is presented. The investigations include the influence of the electrode material, AlN thickness and stress tuning during sputtering on the material parameters, especially the piezoelectric coefficients. It is shown that AlN layers deposited at only 200 °C have good piezoelectric properties. The tuning of residual layer stress has little influence on the piezoelectric properties of AlN. Further two methods of wet chemical etching of AlN are compared. The complete CMOS compatible processing of AlN-based MEMS structures is demonstrated on 200 mm wafers.

This paper presents design, fabrication and measurements for two single-axial resonant driven microscanners with apertures of 1.2 mm and I mm diameter, which achieve large 0,opt ·D-products of 73.2°·mm and 40°·mm at high frequencies of 27 kHz and 60 kHz, respectively. Unipolar rectangular signals with different amplitudes of 15 V and 10 V have been used for driving. The attainment of large tilting angles and high frequencies are resulted from the high torque delivered by the thin-film PZT driving layer and mechanical leverage amplification. To study the influence of geometrical parameters on the static and dynamic performance and optimize the designs, FEM simulations have been applied. In order to realize closed-loop actuation one actuator has been used as piezoelectric sensor delivering corresponding feedback signals for position detection. The simulation and characterization results will be presented and discussed.

In this paper design and fabrication of high speed piezoelectric microscanners are presented. These single axis microscanners with 1 mm(2) mirror area feature thin-film PZT (lead-zirconate-titanate) actuators with high piezoelectric coefficients [1] and mechanical leverage amplification to achieve large deflections. A parametric study by means of analytical modeling and FEM simulations has been performed. A SOI wafer consisting of 80 mu m polysilicon and 1 mu m SiO2 on 725 mu m silicon wafer is used as the substrate, whereon a 2 mu m thick PZT layer is deposited by magnetron sputtering applied for the piezoelectric drives. Various micromirrors with resonant frequencies up to 56 kHz and extrapolated theta(opt)center dot D products up to 60 deg.mm have been designed. Prototypes with these designs have been successfully fabricated in a bulk micromachining process.