Oriented growth of sol-gel-modified PbTiO3 thin films on Si-based substrates

Abstract

A sol–gel Pb0.76Ca0.24TiO3 solution was deposited by spin-coating onto Pt/Ti/SiO2/Si(100), Ti/Pt/Ti/SiO2/ Si(100) and Pt/TiO2/SiO2/Si(100) substrates. As-prepared substrates and those subjected to a thermal treatment in air at 650 °C for 1800 s were used. The wet films were dried at 350 °C for 60 s and crystallized in air by rapid thermal processing (RTP) at 650 °C for 50 s, with a heating rate of ∼30 °C s−1. This procedure was repeated four times to obtain crystalline films with a thickness of ∼250–300 nm. Perovskite films with different textures were obtained after crystallization. This texture was a consequence of the multilayer structure of the substrate. The formation of Pb0.76Ca0.24TiO3 films with a preferred orientation in the 〈 111〉 direction of the perovskite was observed when Ti was present at the top surface of the Pt. Texture of the films was studied by x-ray diffraction (XRD) and the structure of the substrate surfaces was studied by grazing incidence x-ray diffraction (GIXRD). Spontaneous pyroelectric coefficients were measured in the films. Copyright © 2000 John Wiley & Sons, Ltd.