Pyroelectric Microsensors by Sol-Gel Derived PbTiO3 and La-PbTiO3 Thin Films

Abstract

AbstractFerroelectric PbTiO3 and Lanthanum-modified PbTiO3 thin films have been deposited on different substrate surfaces by sol-gel processing. The ferroelectric, dielectric, and pyroelectric properties and their temperature dependences have been investigated. The sol-gel derived thin films were integrated onto a membrane structure fabricated by solid-state surface-micromachining technology. The performance of the resultant devices have been tested as an uncooled infrared detector. The high voltage responsivity and short rise time are attributed to the combination of the pyroelectric film, the underlying polycrystalline silicon layer, and the thermal design of the composite structure. The addition of Lanthanum with a molecular fraction of 3% and 5% has resulted in a lower dielectric loss and a reduced thermal noise.