Effects of LSMO Buffer Layer on Crystalline Orientation and Ferroelectric Properties of Bi2.9Pr0.9Ti3O12 Thin Films Prepared by Radio-Frequency Magnetron Sputtering
WU Yun-Yi1,2, ZHANG Duan-Ming1, YU Jun2, ZHENG Chao-Dan1,2, WANG Yun-Bo2
1School of Physics, Huazhong University of Science and Technology, Wuhan 4300742Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074
Effects of LSMO Buffer Layer on Crystalline Orientation and Ferroelectric Properties of Bi2.9Pr0.9Ti3O12 Thin Films Prepared by Radio-Frequency Magnetron Sputtering
WU Yun-Yi1,2, ZHANG Duan-Ming1, YU Jun2, ZHENG Chao-Dan1,2, WANG Yun-Bo2
1School of Physics, Huazhong University of Science and Technology, Wuhan 4300742Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074
摘要Ferroelectric Bi2.9Pr0.9Ti3O12/La0.67Sr0.33MnO3 (BPT/LSMO) films are fabricated on Pt(111)/TiO2/SiO2/Si substrates by rf-magnetron sputtering method. The influences of the LSMO deposition conditions and LSMO layer thickness on properties of BPT thin films are studied. The LSMO layer deposited at 300°C and 450°C favours preferred (117) orientation of BPT films, while deposited at 600°C for LSMO layer leads to strong (111)-preferred orientation of BPT film. With the LSMO buffer layer, the films exhibit improved ferroelectric properties and Pt/BPT/LSMO(20nm)/Pt capacitor shows the largest remnant polarization Pr of 18.4μC/cm2 at 14V. A similar change in dielectric constant with the increase of LSMO layer thickness is also observed and the highest dielectric constant of 342.7 is obtained for the Pt/BPT/LSMO(20nm)/Pt film. Compared with the Pt/BPT/Pt film, the Pt/BPT/LSMO/Pt films exhibit better fatigue endurance after 5×109 switching cycles. Moreover, the LSMO layer has apparent effect on leakage current density and the Pt/BPT/LSMO(20nm)/Pt film exhibits the lowest leakage current density.
Abstract：Ferroelectric Bi2.9Pr0.9Ti3O12/La0.67Sr0.33MnO3 (BPT/LSMO) films are fabricated on Pt(111)/TiO2/SiO2/Si substrates by rf-magnetron sputtering method. The influences of the LSMO deposition conditions and LSMO layer thickness on properties of BPT thin films are studied. The LSMO layer deposited at 300°C and 450°C favours preferred (117) orientation of BPT films, while deposited at 600°C for LSMO layer leads to strong (111)-preferred orientation of BPT film. With the LSMO buffer layer, the films exhibit improved ferroelectric properties and Pt/BPT/LSMO(20nm)/Pt capacitor shows the largest remnant polarization Pr of 18.4μC/cm2 at 14V. A similar change in dielectric constant with the increase of LSMO layer thickness is also observed and the highest dielectric constant of 342.7 is obtained for the Pt/BPT/LSMO(20nm)/Pt film. Compared with the Pt/BPT/Pt film, the Pt/BPT/LSMO/Pt films exhibit better fatigue endurance after 5×109 switching cycles. Moreover, the LSMO layer has apparent effect on leakage current density and the Pt/BPT/LSMO(20nm)/Pt film exhibits the lowest leakage current density.
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2008, Vol. 25 
