Monolithic Pyroelectric Infrared Sensor Array with Porous SiO2 Film

A simple method to fabricate pyroelectric sensors array using standard semiconductor process on Silicon substrate was investigated. 600 nm porous SiO2 film was prepared by spin coating, working as ultra-thin thermal insulator. Good insulation property was achieved owing to its extremely low thermal conductance. A dense SiO2 layer was made above porous film and provided a smooth surface for sensor fabrication process. Square sensor units of five different sizes from 0.01 mm(2) to 2.25 mm(2) were produced by photolithography and wet etching. The pyroelectric coefficients of these units were in the range of 2.5x10(-9) Ccm(-2)K(-1) to 3.5x10(-9) Ccm(-2)K(-1). Different sensor units showed similar infrared detective performance at frequency range from 5 Hz to 100 Hz. The excellent directivities were capable for applications of next generation infrared array detector.