A Dual-Mode Anemometer Fabricated in 65-nm CMOS BEOL Without Postprocessing

A thermal anemometer was industrially fabricated without any preprocessing, coprocessing, or postprocessing for the first time. The total sensor footprint is only 0.245 mm² using TSMC’s 65-nm CMOS process. The dual-mode anemometer measures wind speeds up to 1.2 m/s with a precision of 3.1 % (or 0.037 m/s) calorimetrically. Alternatively, using the second hot-element mode, the sensor measures in the range of 0–7.5ms⁻¹ with a 0.1 m/s accuracy and an average 1.34 % precision. This is the first industrially fabricated thermopile-based CMOS anemometer, paving the way for a compact foundry SoC with inbuilt underlying computing for low-cost air speed monitoring.