Pyroelectric Thin Film Presence Detector Arrays with Micromachined Pixels

Lately, pyroelectric thin film detectors gain in significance in the field of presence detection. In the paper, different variants of Pb(ZrTi)O 3 based detector arrays with 8 to 256 pixels are introduced. The sensing elements are arranged on thin micromachined SiO 2 /Si 3 N 4 membranes [1-4] as mechanical supporting structure with both low thermal mass and low heat conductivity into the substrate to achieve a high detectivity. For shaping these membrane structures, the most promising technology is micromachining, either from back or from surface of the silicon substrate. Self-polarized PZT thin films with a pyroelectric coefficient p up to 2.1 * 10 m 4 C/(m 2 K), dielectric loss tan i of less than 0.01 and a dielectric coefficient l r of about 250 are deposited in a multi-target sputtering process at comparatively low substrate temperatures of about 520°C. In the paper, presence detectors using thin film pyroelectric IR detector arrays as well as detector design, detector simulation, detector manufacturin...