Abstract
This study demonstrates a vertically integrated environment sensor with a fluorescence quenching based gas sensor [1] and a resistive temperature detector (RTD) using the TSMC standard CMOS process (Fig. 1a). Features of this study are (Fig. 1): (1) integration of photo-sensors, thermal-isolation structure, temperature, and optical based gas-sensing films using CMOS and polymer dispensing technologies, (2) multiple optical sensors equipped with thermal compensation unit (thermometer) are monolithically integrated, (3) heterogeneous integration with LED can reduce the size of gas sensor, (4) various sensing films can be prepared for multiple gases detection. Measurements show the results of sensitivity at room temperature and under influence of temperature variation. A sensitivity of 19.7 (μA/%) for O 2 (sensing range: 16-50% oxygen concentration) is achieved at room temperature and the sensitivity of the gas sensor decreases from 9.2μA/% to 1.7μA/% as the environment temperature increases from ∼40°C to ∼80°C. The monolithically integrated thermometer enables the on-site temperature monitoring for sensing signal compensation.