Carbon Nanotube-Based CMOS Gas Sensor IC: Monolithic Integration of Pd Decorated Carbon Nanotube Network on a CMOS Chip and Its Hydrogen Sensing

The integration of carbon nanotube (CNT)-based sensor and readout complementary metal-oxide-semiconductor integrated chip (CMOS IC) to detect hydrogen gas in a single chip is presented. First, we have fabricated the CMOS IC using the standard 0.35-μm CMOS process. Then, we have built 8 × 8 CNT-based sensor cells on it using a proposed tractable postprocessing strategy and judicious electrode scheme. The fabricated sensor IC can operate down to 10-ppm concentration of hydrogen in air as a hydrogen sensor. This paper is expected to have a major impact upon the integration of the CNT technology with CMOS technology and be extended to the development of CMOS IC integrated with various nanomaterials.