Self-Heating CMOS Flow Sensor

Abstract

This paper reports a new design of polysilicon flow sensor fabricated by UMC $0.18\ \mu \mathrm{m}$ CMOS MEMS foundry. Our self-heating design is different from the conventional one which has floating plate with resistive temperature detectors (RTDs) heated by another heater aside, and our self-heating RTD half-bridge is only $300\times 250\ \mu \mathrm{m}^{2}$ in chip size. This new design outputs a normalized sensitivity of $138\ \mu \mathrm{V}/\mathrm{V}/(\mathrm{m}/\mathrm{s})$ within the speed range of 0-15 m/s. This sensitivity is 89% of Y.-K. Lee's work in IEEE MEMS 2020. The dummy specimen and the orientation-free wind tunnel tests also confirmed the sensor performance.