The Study of RF-Magnetron-Sputtered (PbBa)(PbZr)O3 Thin Film

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In this work, a new system of sputtered thin films with the composition of (Pb2+1-xBa2+x)(Pb4+1-yZr4+y)O3 (PBZ) were studied. A preferred (100) and (200) texture of PBZ films have been formed on the LaNiO3 (LNO) electrode due to the enhancement from the strong (100) and (200) texture of LNO. The Pb content of the films can be modulated by the excess PbO in the target and the change of substrate temperatures. A simulation model with the composition of the form, (Pb1-xBax)(Pb1-yZry)O3, is proposed to explain the intensity difference in (100) and (200) peaks depending on the Pb4+ content. The compositions obtained from the simulated results are consistent with those from the fitting of XPS spectrum of Pb 4f7/2. The electrical properties as well as the XRD intensity difference are closely related to the Pb4+ content in PBZ films. A phase transformation from ferroelectric to paraelectric occurs with increasing the Pb4+ content from 0~0.12 to 0.2~0.22 in the PBZ films. For the Pb4+ content less than 0.22, the film performs good electrical properties. The leakage current can be maintained below 10-7 A/cm2 and the breakdown electric field is as high as 550 KV/cm, along with dielectric constant of 350, remanent polarization of 17 μC/cm2 and coercive field of 310 KV/cm. Therefore, thin PBZ film is a promising candidate for low leakage and high charge storage applications in FRAM.