Pyroelectric PbTiO/sub 3/ thin films for microsensor applications

Abstract

Pyroelectric lead titanate thin films (PbTiO/sub 3/) deposited by sol-gel processing have been characterized for possible use in microsensor applications. Pyroelectric properties, crystalline phase, dielectric coefficient, and ferroelectric properties have been investigated. The measured room-temperature pyroelectric coefficient in 0.6- mu m-thick films is 90 nC/cm/sup 2/-K. Based on a comparison of relevant properties with other IC-compatible pyroelectric materials, PbTiO/sub 3/ offers the possibility of achieving an extremely high pyroelectric coefficient over a wide operating temperature range. The authors present the use of PbTiO/sub 3/ as a pyroelectric material integrated with polysilicon microbridge technology. The formation of composite sol-gel PbTiO/sub 3/ thin films on 1.0- mu m-thick polysilicon membranes offers a key advantage of implementing both a low thermal mass and a high pyroelectric sensitivity for uncooled infrared detection.<>