Preparation of Si-based PZT pyroelectric thick film infrared detector

Lead zirconate titanate (PbZr0.3Ti0.7O3) thick films and single element detectors for pyroelectric applications were fabricated on Si (100) substrates by MEMS and screen-printing technology. The preparation method and device processing technology were studied in detail. Firstly, the silicon-cup was etched by tetra-methyl ammonium hydroxide (TMAH) solution. Secondly, the Al2O3 barrier layer was prepared to prevent Si diffusion between PZT/ Si through reactive radio frequency (RF) sputtering. Cool isostatic pressing experiments were conducted in order to increase the density of PZT thick films. Finally, the PZT ceramic thick films about 30 m were achieved at a low sintering temperature about 850 ℃. The dielectric permittivity and loss angle tangent tested at 1 kHz under 25℃ were 210 and 0.017 respectively. By using dynamic current method, pyroelectric coefficient of the PZT thick film was determined to be 1.5 10 -8 Ccm-2K-1. The detectivity of detector with 3 mm3 mm area was measured by mechanically chopped blackbody radiation as the function of frequency. The results show that the single element detector obtains its maximum detectivity 7.4107 cmHz1/2W-1 at 112.9 Hz.