Characterization and control of a MEMS-based fast steering mirror

The semiconductor industry continues to push the boundaries of microchip miniaturization, while also requiring high yield and throughput. ASML is a leading company that drives this advancement, thanks to its lithography and metrology systems, which enable the progression of Moore's Law by overcoming the technology nodes. This thesis project has been carried out at ASML with the goal of characterizing a Micro Electro Mechanical System (MEMS)-based Fast Steering Mirror (FSM) and prototyping a a precise beam control system for optical applications. MEMS-based FSM devices are commonly used in optical communications, LiDAR sensing, adaptive optics and beam alignment. They have advantages over other beam steering technologies including improved bandwidth and reduced size and cost. In this work, a characterization setup has been built in order to measure the FSM performance using two methods. The first employs a quadrant photodetector to evaluate speed, bandwidth, reproducibility, and accuracy. The second one uses a camera sensor to measure in-motion effects such as 'blurring', related to the mirror stability and trace repeatability. Control techniques and their implementation in software and hardware is discussed. The mirror demonstrated a very high bandwidth, reproducibility and accuracy. And overall the results confirm the suitability of MEMS-based FSMs for high-throughput, precision-demanding optical systems for semiconductor manufacturing.