Today, MEMS devices while continuing to maintain their novelty are for the most part no longer a new class of device technology – in fact the highest volume MEMS products IMUs, BAW/SAW filters, Microphones, Pressure Sensors, and Ink Jet devices are from a market entry perspective, considered mature. Despite this, they’re tirelessly evolving and continuing to bring new materials and unit process challenges. With each new design that leverages new materials or combinations of materials, together with increasingly challenging unit processes, the sophistication of the required metrology and inspection steps increases. This brief presentation will address a few of those challenges and explain the value that novel inspection and metrology capabilities can bring to both device manufacturers and equipment OEMs in characterizing their high-volume manufacturing processes and/or process development cycles. In doing so, optical critical dimension (OCD), infra-red (IR) inspection and acoustic metrology technologies will be highlighted in the context of IMU, Microphone, Piezo and finally bulk acoustic wave (BAW) filter device fabrication.