Novel micromachined thermal anemometer based on lateral polysilicon diode flow sensor

A new micromachined thermal anemometer based on laterally polysilicon diode (LPD) temperature-sensing elements is developed in the paper. The LPD was fabricated with CMOS compatible process and its temperature-sensing characterization is also investigated. The measured results show the forward current increases with temperature near linearly. The temperature coefficient is about 1.8mV/K, which is close to that of monocrystalline silicon diode. A anemometer with a ring-like polysilicon heater and 8 LPD temperature-sensing elements were fabricated and characterized, air flow up to 120 cm3/s was measured and more than 8 directions of wind can be detected.