Electrical properties of photo-CVD boron-doped hydrogenated nanocrystalline silicon-carbide (p-nc-SiC : H) films for uncooled IR bolometer applications

Abstract

Electrical properties of boron-doped nanocrystalline silicon-carbide (p-nc-SiC:H) films grown by mercury-sensitized photo-chemical vapor deposition method have been investigated for uncooled IR bolometer applications. The temperature coefficient of resistance (TCR), conductivity, and l/f noise characteristics have been measured and the detectivity of a bolometer has been estimated from them. It has been observed that as ethylene gas flow ratio (C2H4/SiH4) increases, TCR of films increases due to larger optical bandgap. However, the l/f noise also increases due to the reduction of the number of total carriers in the films for higher activation energy (E-a). The maximum TCR of 2.3%/K has been measured for the films deposited with an ethylene gas flow ratio of 0.47, while the maximum detectivity has been estimated for those with an ethylene gas flow ratio of 0.07 because of the lowest l/f noise. (C) 2003 Elsevier Science B.V. All rights reserved.