Uncooled Infrared Micro-Bolometer FPA for Multiple Digital Correlated Double Sampling

Abstract

This letter presents the design, simulation, and fabrication of an uncooled infrared micro-bolometer focal plane array (MBFPA) for multiple digital correlated double sampling (MD-CDS) to reduce a large amount of fixed pattern noise (FPN). A hydrogenated amorphous silicon-based MBFPA is fabricated with $80\times 60$ active cell array and $80\times 9$ proposed warm cell array with a 35- $\mu \text{m}$ pitch. The proposed warm cell can be formed simply by using additional thermal paths on the active cell and it closely matches the properties of the active cell, including thermal conductance and capacitance, resistance, and structure. Averaged reference signals generated by the warm cell array during readout have the same FPN as the active cell without reaction from incident infrared. Experimental results show that FPN is 23% reduced by using the proposed warm cell array and the measured noise equivalent temperature difference referred to $f$ /1.0 is 103 mK after the MD-CDS.