CMOS Humidity Sensor System Using Carbon Nitride Film as Sensing Materials

Sung Pil Lee; Ji Gong Lee; Shaestagir Chowdhury

doi:10.3390/s8042662

CMOS Humidity Sensor System Using Carbon Nitride Film as Sensing Materials

Sensors (Basel). 2008 Apr 14;8(4):2662-2672. doi: 10.3390/s8042662.

Authors

Sung Pil Lee¹, Ji Gong Lee², Shaestagir Chowdhury³

Affiliations

¹ Department of Electronic Engineering, Kyungnam University, Masan, Kyungnam 631-701, Korea. sensors@kyungnam.ac.kr.
² Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio 44106, USA.
³ Intel Corporation, Hillsboro, OR 97124, USA.

Abstract

An integrated humidity sensor system with nano-structured carbon nitride film as humidity sensing material is fabricated by a 0.8 μm analog mixed CMOS process. The integrated sensor system consists of differential humidity sensitive field effect transistors (HUSFET), temperature sensor, and operational amplifier. The process contains two poly, two metal and twin well technology. To form CN_x film on Si₃N₄/Si substrate, plasma etching is performed to the gate area as well as trenches. CN_x film is deposited by reactive RF magnetron sputtering method and patterned by the lift-off technique. The drain current is proportional to the dielectric constant, and the sensitivity is 2.8 ㎂/%RH.

Keywords: CMOS; Carbon nitride film; Humidity; Integrated sensors.