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 3.3 V larger than that on SiO2. In addition, well-behaved capacitance-voltage characteristics are only obtained in PbTiO3/Al2O3 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 × 10-7 A cm-2 at -2.5 V, which is low enough for deep sub-μm application.
- Dielectric constant
- Thin films