Abstract
This study presents the vertical integration of humidity sensor, pressure sensor and thermometer on a single chip (Fig. 1) based on the TSMC 0.18 μm 1P6M CMOS platform. Merits of the proposed sensing hub are: (1) Vertical SoC: vertically integrated environmental sensing hub consisting capacitive humidity sensor with microheater integrated, capacitive pressure sensor, and diode thermometer, (2) Novel humidity sensor: fast response and easily fabricated air-based capacitive humidity sensor. Measurements demonstrate the feasibility and performances of proposed environmental sensing hub (400 μm 400 μm): humidity sensor with sensitivity of 3.32 fF/%RH and response time of 2.48 sec, pressure sensor with sensitivity of 0.22 fF/kPa, and thermometer with response of 0.64 mV/.