Carbon nanotube microbolometers on suspended silicon nitride via vertical fabrication procedure

Abstract

We report on carbon nanotube membrane microbolometers, operating uncooled in the near-infrared (IR) and mid-IR band, with speed of 10 ms and responsivity of several kV/W. The microbolometers were fabricated using a vertical process on a thin suspended silicon nitride film for thermal isolation. The measured detectivity was ∼5.5 × 106 cm Hz1/2 W−1 at 40 Hz. The broadband spectral responses measured at room temperature over the entire band of the IR illumination source are characteristic of bolometric response. These results are indicative of the potential of this platform for uncooled IR sensing and thermal imaging. The measured device noise indicated a relatively strong 1/f contribution, which is common of carbon nanotube devices operated in atmospheric conditions. The observed responses suggest, however, that oxygen adsorption/desorption reported by some researchers did not play a significant role in these devices.