The design, processing, evaluation and characterization of pyroelectric PVDF copolymer/silicon MOSFET detector arrays

We have developed a 64 element linear array of pyroelectric elements fully integrated on silicon wafers with MOS readout devices. The ferroelectric polymer film sensor deposited and polarized on the extended gate of the MOSFET results in a hybrid circuit, the pyroelectric-oxide-semiconductor field effect transistor (POSFET). The fabrication of the wafers included the design of the various masks required to produce the layers which made up the transistor array: stopper layer, active layer, poly-silicon layer, contacts layer, and bottom electrode layer. A thin film of the ferroelectric copolymer P(VDF/TrFE) was spin coated onto the wafer. Patterned gold electrodes were sputtered as the top electrode layer. The ferroelectric copolymer was hysteresis poled in situ. Tests performed included the array's response to a CO₂ laser operating in the CW and single pulse modes at 10.6 μm. We present details of the design, processing, and testing of the fabricated devices