The Effects of Oxygen Partial Pressure on Interface States and Ferroelectric Properties of PZT/PbO/Si (MFIS) Structures
Pt/PZT/PbO/Si with the MFIS structure was deposited on the p-type (100) Si substrate by the r.f. magnetron sputtering method with Pb1.1Zr0.53Ti0.47O3 and PbO targets. From the X-ray photoelectron spectroscopy (XPS) results, we could confirm that the partial pressure ratio during PbO deposition affects the interface condition of PbO/Si and the chemical state of Pb existing at the surface of the PZT thin film. The maximum value of the memory window is 3.0 V under the applied voltage of 9V for Pt/PZT (200 nm 400°C)/PbO (80 nm, 300°C)/Si structures with the PbO buffer layer deposited at the partial pressure of 7:3. From these results, we could assume that the PbO buffer layers play a role of the diffusion barrier between the PZT thin film and the Si substrate as well as the seed layer.
Hyungsun Kim, Junichi Hojo and Soo Wohn Lee
C. H. Park et al., "The Effects of Oxygen Partial Pressure on Interface States and Ferroelectric Properties of PZT/PbO/Si (MFIS) Structures", Materials Science Forum, Vols. 544-545, pp. 1077-1080, 2007