Micro-machined pyroelectric thin film IR sensors

In this paper, we report our recent success in preparation and fabrication of Si-based pyroelectric thin film micro-IR sensors using micro-machining technology and systematical characterization results. Ferroelectric PT, PZT, PLZT and multilayered PZT/PT, PZT/PLZT thin films have been prepared on the Pt coated silicon wafer using a modified sol-gel method. These feffoelectric thin films have been patterned and micro-machined to make thin film infrared sensors and prototype pyroelectric IR devices on Si membrane have been obtained. The interesting self-biased phenomenon has been observed in PZT/PLZT multilayer IR sensors, and it is found that the polarization in ferroelectric thin films is strongly correlated to the pyroelectric property. Experimental results also show that multilayer approach is an important technique in improving the pyroelectric responses.