Synthesis and characterization of carbon nitride films for micro humidity sensors

Abstract

Nano-structured carbon nitride (CNx) films were synthesized by a reactive RF magnetron sputtering system with a DC bias under various deposition conditions, and their physical and electrical properties were investigated with a view to using them for micro humidity sensors. The FTIR spectra of the deposited films showed a C=N stretching band in the range of 1600-1700 cm -1, depending on the amount of nitrogen incorporation. The carbon nitride films deposited on the Si substrate had a nano-structured surface morphology with a grain size of about 20 nm, and their deposition rate was 1.5 μm/hr. The synthesized films had a high electrical resistivity in the range of 108 to 109 Ω·cm, depending on the deposition conditions. The micro humidity sensors showed a good linearity and low hysteresis between 5∼95 %RH. © 2008 by MDPI.