EPITAXIALLY GROWN PYROELECTRIC INFRARED-SENSOR ARRAY FOR HUMAN-BODY DETECTION

A high performance pyroelectric infrared sensor array based on epitaxi ally grown Pt and La-modified PbTiO3 (PLT) thin films is fabricated by RF magnetron sputtering and micromachining technology. A single detec tor element forms a ferroelectric thin film capacitor epitaxially grow n on a single crystal MgO substrate. The heat loss and the noise level are minimized by etching the substrate that leads to reduced thermal mass. Micromachining technology is used to support the fragile MgO sub strate membrane by coating polyimide on top of the detector elements. The sensor array is mounted on a dip-type package sealed by a Silicon filter with anti-reflection coating to transmit 8-10 mu m wavelength i nfrared radiation from a human body. It shows a very high detectivity of 8.5x10(8) cm .root Hz/W and it is primarily due to the highly c-axi s oriented epitaxially grown PLT thin film capacitor with the minimize d thermal mass.