Preparation of highly C-axis-oriented PZT films on Si substrate with MgO buffer layer by the sol–gel method

Lead zirconate titanate (Pb(Zr,Ti)O3, PZT) thin films have received much attention due to their excellent dielectric, ferroelectric and piezoelectric properties. Epitaxial growth of PZT films on Si substrate is desirable to integrate ferroelectric devices and semiconductor devices on the same substrate. However, epitaxy of PZT films directly on Si substrates is very difficult because of the lattice mismatch between them and the interdiffusion owing to the high growth temperature during deposition. In this paper, we study the effect of MgO buffer layer and the post-annealing conditions on the C-axis orientation of the PZT films fabricated by the sol–gel method on Si substrate. The experimental results show that if we anneal the PZT films grown on MgO (2 0 0)/Si substrate at 600 °C for 1 h, highly C-axis-oriented PZT films could be obtained. The full width at half maximum intensity (FWHM) of PZT (0 0 1) and PZT (0 0 2) peaks obtained from the X-ray diffraction (XRD) were 0.18° and 0.22°, respectively. The surface roughness of the annealed PZT films was about 3.9 nm. The results could be useful in the integration of ferroelectric devices and semiconductor devices on the same Si substrate.