Growth and properties of PbTiO3/Pb(Zr, Ti)O3 heterostructures deposited by sputtering on Si substrates

Pb(Zr, Ti)O-3 (PZT) films with very thin PbTiO3 (PT) buffer layers inserted between the film and the Si/SiO2/Ti/Pt substrate were prepared by radio-frequency (r.f.) magnetron sputtering. The effects of PT buffer layer to the PZT films phase formation, dielectric and ferroelectric properties was studied. By using the PT buffer layer, polycrystalline him without buffer layer changed to highly (100) or (111) oriented PZT films depending of the buffer layer preferred orientation. The buffer layer orientation was controlled by the growth temperature. Intermediate PT layers enhance the perovskite phase formation; the perovskite PZT films on PT buffer layer were obtained at annealing temperature as low as 450 degrees C instead of 625 degrees C without buffer layer. The dielectric constant and the ferroelectric properties were evaluated function of the buffer layer growth temperature and thickness. The fatigue behavior of the PT/PZT composite thin films was compared with that of PZT thin film on Pt layer. The fatigue of PZT films was improved through insertion of PT buffer layer.