Effects of post annealing on the material characteristics and electrical properties of La doped BaTiO3 sputtered films

被引:6
作者
Wu, C. H. [2 ]
Chu, J. P. [1 ]
Wang, S. F. [3 ]
Lin, T. N. [5 ]
Chang, W. Z. [2 ]
John, V. S. [2 ,4 ]
机构
[1] Natl Taiwan Univ Sci & Technol, Dept Polymer Engn, Taipei 10607, Taiwan
[2] Natl Taiwan Ocean Univ, Inst Mat Engn, Chilung 202, Taiwan
[3] Natl Taipei Univ Technol, Dept Mat & Minerals Resources Engn, Taipei 106, Taiwan
[4] TDMNS Coll, Dept Phys, T Kallilulam 627113, India
[5] Inst Nucl Res Energy, Div Chem Engn, Longtan 320, Taiwan
关键词
BaTiO3; La dopant; Magnetron sputtering; XPS; Dielectric constant; Leakage current density;
D O I
10.1016/j.surfcoat.2008.06.112
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
La-doped BaTiO3 thin films with 200 nm thickness were fabricated by r.f. magnetron sputtering system onto Pt/Ti/SiO2/Si substrates. The effects of post-annealing and the amount of dopant on microstructure and electrical proper-ties were studied. The X-ray diffraction (XRD) study reveals that, the film becomes crystallized when the annealing temperature is above 550 degrees C. In addition, all the films show tetragonal BaTiO3 crystal structure without any second phase or reaction phase formation after annealed at 750 degrees C. The X-ray photoelectron spectroscopy (XPS) results provide the evidence to support the existence of La2O3 with excess of BaTiO3 structure, when the dopant content reaches more than 1.4 at.%. The dielectric constant also increases with increasing annealing temperature and it may be due to the better crystallinity and larger grain sizes. The 0.1 La film annealed at 750 degrees C shows a high dielectric constant of 487 measured at 1 MHz. The doped film in the as-deposited condition yields a reduction of leakage current was also observed. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
引用
收藏
页码:5448 / 5451
页数:4
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