Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Chamber Pressure on Dielectric Properties of Sputtered MgTiO3 Films for Multilayer Ceramic Capacitors

  • Park, Sang-Shik (School of Nano & Materials Engineering, Kyungpook National University)
  • Received : 2010.06.29
  • Accepted : 2010.07.19
  • Published : 2010.07.27
Download PDF
⟨ Previous Next ⟩

Abstract

$MgTiO_3$ thin films were prepared by r.f. magnetron sputtering in order to prepare miniaturized NPO type MLCCs. $MgTiO_3$ films showed a polycrystalline structure of ilmenite characterized by the appearance of (110) and (202) peaks. The intensity of the peaks decreased with an increase in the chamber pressure due to the decrease of crystallinity which resulted from the decrease of kinetic energy of the sputtered atoms. The films annealed at $600^{\circ}C$ for 60min. showed a fine grained microstructure without micro-cracks. The grain size and roughness of the $MgTiO_3$ films decreased with the increase of chamber pressure. The average surface roughness was 1.425~0.313 nm for $MgTiO_3$ films prepared at 10~70 mTorr. $MgTiO_3$ films showed a dielectric constant of 17~19.7 and a dissipation factor of 2.1~4.9% at 1MHz. The dielectric constant of the films is similar to that of bulk ceramics. The dielectric constant and the dissipation factor decreased with the increase of the chamber pressure due to the decrease of grain size and crystallinity. The leakage current density was $10^{-5}\sim10^{-7}A/cm^2$ at 200kV/cm and this value decreased with the increase of the chamber pressure. The small grain size and smooth surface microstructure of the films deposited at high chamber pressure resulted in a low leakage current density. $MgTiO_3$ films showed a near zero temperature coefficient and satisfied the specifications for NPO type materials. The dielectric properties of the $MgTiO_3$ thin films prepared by sputtering suggest the feasibility of their application for MLCCs.

Keywords

References

  1. Y. Jiang, R. Guo and A. S. Bhalla, J. Phys. Chem. Solids, 59, 611 (1998). https://doi.org/10.1016/S0022-3697(97)00244-8
  2. M. P. Baura-Pena, M. J. Martinez-Lope and M. E. Garcia-Clarel, J. Mater. Sci., 26, 4341 (1991). https://doi.org/10.1007/BF00543648
  3. T. Nomura, N. Kawano, J. Yamamatsu and T. Arashi, Jpn. J. Appl. Phys., 34, 5389 (1995). https://doi.org/10.1143/JJAP.34.5389
  4. Y. Okino, H. Sizuno, S. Kusumi and H. Kisi, Jpn. J. Appl. Phys., 33, 5393 (1994). https://doi.org/10.1143/JJAP.33.5393
  5. J. Yamamatsu, N. Kawano, T. Arashi, A. Sato, Y. Nakano and T. Nomura, J. Power Sources., 60, 199 (1996). https://doi.org/10.1016/S0378-7753(96)80011-5
  6. Y. Sakabe, Y. Takeshima and K. Tanaka, J. Electroceram., 3, 115 (1999). https://doi.org/10.1023/A:1009986825169
  7. R. Xu, M. Shen, S. Ge, Z. Gan and W. Cao, Thin Solid Films, 406, 113 (2002). https://doi.org/10.1016/S0040-6090(02)00050-0
  8. Y. Takeshima, T. Tanaka and Y. Sakabe, J. Am. Ceram. Soc., 106, 441 (2000).
  9. S. Park, Integrated Ferroelectrics, 74, 87 (2005) https://doi.org/10.1080/10584580500413962
  10. L. T. Lamont and A. Lange, J. Vac. Sci. Technol., 7, 198 (1970). https://doi.org/10.1116/1.1315794
  11. Y. Zhao, Y. Qian, W. Yu and Z. Chen, Thin Solid Films, 286, 45 (2002).
  12. J. Bernard, D. Hpuivet, J. El Fallah and J. M. Haussonne, J. Eur. Ceram. Soc., 24, 1877 (2004). https://doi.org/10.1016/S0955-2219(03)00461-8
  13. K. Wakino, Ferroelectrics, 91, 69 (1989). https://doi.org/10.1080/00150198908015730
  14. Y. H. Choi and J. Lee, Thin Solid Films, 385, 43 (2001). https://doi.org/10.1016/S0040-6090(00)01896-4
  15. V. M. Ferreira, J. L. Baptista, S. Kamba and J. Petzelt, J. Mater. Sci., 28, 5894 (1993). https://doi.org/10.1007/BF00365198