Ferroelectric properties of sol-gel delivered epitaxial Pb(Zrx,Ti1−x)O3 thin films on Si using epitaxial γ-Al2O3 Layers

This letter reports on the fabrication and investigation of ferroelectric epitaxial Pb(Zr,Ti)O3(PZT)∕Pt films on Si substrates using epitaxial γ-Al2O3 buffer layer for Si integrated ferroelectric devices. (001) and (111) epitaxial γ-Al2O3 films were grown on Si(001) and Si(111) substrates, respectively, using chemical vapor deposition. PZT films with various compositions were epitaxially grown on epitaxial Pt coated substrates using a sol-gel method. Epitaxial PZT films exhibited better ferroelectric and pyroelectric properties than polycrystalline PZT films. In particular, maximum pyroelectric coefficients of the epitaxial films were obtained, with values of 1.8×10−8C∕cm2K for the PZT(001) film with a Zr∕Ti ratio of 40∕60 and 1.4×10−8C∕cm2K for the PZT(111) film with a Zr∕Ti ratio of 52∕48.