Electrical and structural characteristics of PbTiO3 thin films with ultra-thin Al2O3 buffer layers

Abstract

Polycrystalline PbTiO3 thin films have been prepared on Si substrates with ultra-thin SiO2 and Al2O3 buffer layers by chemical solution deposition, respectively. Although capacitance-voltage characteristics show hysteresis loops in both cases, the memory window of PbTiO3/Al2O3 stacked dielectric is 3.3V larger than that on SiO2. In addition, well-behaved capacitance-voltage characteristics are only obtained in PbTiO3/Al(2)o(3) and the PbTiO3 films on Al2O3 have the dielectric constant of 116 larger than 42 of PbTiO3 films on SiO2. The leakage current density of PbTiO3/Al2O3 dielectric is 1.3 x 10(-7) A cm(-2) at -2.5 V, which is low enough for deep sub-mum application. (C) 2002 Elsevier Science B.V. All rights reserved.