Optical characterization of dynamics on Si-capped MEMS
Visualization of dynamic response is key to testing and developing MEMS devices. This is indispensable for validating FE calculations and determining cross-talk effects. The innovative and patented MSA-650 IRIS Micro System Analyzer allows for measuring true MEMS dynamics by characterizing both in-plane and out-of-plane motions through silicon encapsulation without contact, without need for preparing nor decapping the device. The step of MEMS capping in fabrication processes may result in additional stress, which might alter the device performance. Therefore, a comprehensive characterization of the MEMS device in its final and encapsulated state is needed and indispensible.
Highlights
- Superior separation of individual device layers in capped MEMS delivers the true dynamical MEMS behaviour
- Extracting real-time motion data even from complex-structured Si-capped MEMS
- High resolution modal data up to 25 MHz
- Straighforward FE model validation of MEMS in final state
- Integrated high performance IR microscope allows for measuring through Si walls
- Video microscope measuring mode revealing in-plane motion up to 2.5 MHz
- Standard data export formats for modal data, graphics and video for direct post-processing
Modal testing of silicon encapsulated MEMS
Laser-Doppler-Vibrometry (LDV) is a well-established technique to study the mechanical dynamics of MEMS with utmost precision. However, most laser vibrometers work at visible wavelengths for which the silicon encapsulation is opaque and inhibits MEMS inspection. Thus, LDV testing of such MEMS via visible wavelengths requires either un-encapsulated MEMS or to decap the device.
With a dedicated IR camera and a low-coherence SLD source the MSA-650 IRIS is the worldwide first measurement system with this technology to measure in-plane vibration on encapsulated silicon MEMS with down to 30 nm resolution and real-time out-of-plane vibrations up to 25 MHz with picometer resolution and below. Polytec’s brand new interferometer technology now delivers supreme data quality due to superior separation of individual device layers in capped MEMS devices.
Accessories and components
Tripods, test stands, positioning stages
A-STD-TST-01 Test Stand
Test stand providing ample workspace. With motorized z-axis, travel range 200 mm.
A-STD-BAS-02 Base Stand
Rigid support for the sensor head. Includes manual focus block with 100 mm travel range with coarse and fine drive. Interfaces to commercially available optical tables.
A-STD-F50 Focus Block
Travel Range 50 mm. With coarse and fine drive for manual z-axis adjustment of the sensor head. Interfaces with commercially available wafer probe stations.
Vibration isolation, breadboards
A-TAB-AIR-01 Active Vibration Isolation Table
Air-damped vibration isolation table with active level adjustment. Compatibility: A-STD-TST-01 Test Stand, A-STD-BAS-02 Base Stand.
A-TAB-ELC-01 Active Vibration Isolation Table
Electronically controlled voice coil stabilization for highest isolation performance. Compatibility: A-STD-TST-01 Test Stand, A-STD-BAS-02 Base Stand.
A-BBO-ME02 Breadboard
Breadboard with metric hole pattern. Footprint 900 mm x 600 mm. Compatibility: A-STD-BAS-02 Base Stand.
A-AVI-MELA Active Vibration Isolation Breadboard
Electronically controlled for highest vibration isolation performance. With metric hole pattern. Footprint 600 x 800 mm. Compatibility: A-STD-BAS-02 Base Stand.
Miscellaneous
MSA-A-WPM Wafer Prober Module
Together with the A-PST-200P XY Positioning Stage, the wafer prober module forms a motorized platform for electrical contacting and high-precision measurement of wafers and substrates up to 200 mm in diameter.
Related products
Analyseur de microstructures MSA-600
Système de mesure tout-en-un pour la caractérisation 3D statique et dynamique des MEMS et des microstructures. Le MSA-600 améliore les processus de développement et de contrôle qualité. Intégré aux stations sous pointes disponibles dans le commerce, il permet des tests au niveau des wafer.
Analyseur de microstructures 3D MSA-100
L'analyseur de microstructures saisit simultanément des composantes vibratoires dans les trois directions spatiales. Il permet l'analyse 3D de vibrations haute résolution avec une résolution d'amplitude de l'ordre du sous-picomètre pour des composantes vibratoires dans le plan et hors plan.
Analyseur de microstructures MSA-050
Le vibromètre sous microscope d’entrée de gamme permet de saisir des vibrations sur l’ensemble de la surface de petits éléments et de microstructures. Il fonctionne parfaitement sans contact et mesure la de petits objets avec une extrême précision.