Characterization of sidewall roughness for silicon microstructures in micro actuator

Thermal micro actuators are fabricated using deep reactive ion etching (DRIE) technique on silicon on insulator (SOI) substrates. The sidewalls of silicon microstructure in micro actuator are used as optical interfaces with the fibers. Line edge roughness (LER) of reflective sidewalls is essential to device performance. A method is presented through analyzing high-resolution top-down scanning electron microscope (SEM) images to characterize sidewall line edge roughness (LER) of Si microstructures in thermal micro actuator, only conventional SEM scanning technique is required.