Advanced Microscopy Applications
Micro Nano Fabrications

MEMS

Model: Lucent T model

Modes used – AFM, WLI

Metrology for MEMS devices is a crucial quality control step. The AFM probe itself is a MEMS device. Tight tolerance in dimensions is a must to maintain the properties like stiffness and resonance frequency. Often the probes have coatings for reflection or conductivity. The surface roughness is linked to the damping behaviour and also the reflection efficiency. The Lucent T model was used in the WLI mode to obtain surface profile over ROI of about 500 µm x 500 µm area. Reconstructed profile provides the height of the microfabricated ridge (9 µm). However the slopes can’t be well resolved in WLI. This region is imaged with AFM to reveal the inclination, roughness and also the grain structure. The AFM and WLI modes complement each other to comprehensively characterize MEMS devices. µ