PT(PbTiO3) buffer layer effects on the electrical properties of Pb(Zr,Ti)O-3 thin films

Abstract

PZT(48/52) thin films have been grown on (111)Pt/SiO2/Si substrate by DC-reactive sputtering using multi-target and the effect of PbTiO3(PT) buffer layer to the phase formation of PZT thin films and dielectric properties was studied. By using the PT buffer layer, polycrystalline film without buffer layer changed to highly (100) oriented films at the deposition temperature of 550 degrees C. This crystalline structure change can be resulted from PT buffer preferred orientation at the initial growing stage in which PT buffer can be easily grown (100)(001) orientation. Dielectric constant was increased by using 35 Angstrom, and 70 Angstrom, buffer layer, whereas decrease above 70 Angstrom due to increased PT layer. Hence, optimum thickness of PT buffer layer for PZT thin films is between 35 and 70 Angstrom. PT buffer can effectively remove the low dielectric layer as known from no thickness dependency of dielectric constant.