$O_2$RTA 방법으로 제조된 $Ta_2O_{5-x}$ 박막의 전기적 특성

A Study on Electrical Properties of $Ta_2O_{5-x}$ Thin-films Obtained by $O_2$ RTA

  • 김인성 (한국전기연구원 전자기소재그룹) ;
  • 송재성 (한국전기연구원 전자기소재그룹) ;
  • 윤문수 (한국전기연구원 전자기소재그룹) ;
  • 박정후 (부산대 공대 전자전기통신공학부)
  • 발행 : 2002.08.01

초록

Capacitor material utilized in the downsizing passive devices and integration of passive devices requires the physical and electrical properties at given area such as capacitor thickness reduction, relative dielectric constant increase, low leakage current and thermal stability. common capacitor materials, $Al_2O_3$, $SiO_2$, $Si_3N_4$, $SiO_2$/$Si_3N_4$, TaN and et al., used until recently have reached their physical limits in their application to integration of passive devices. $Ta_2O_{5}$ is known to be a good alternative to the existing materials for the capacitor application because of its high dielectric constant (25~35), low leakage current and high breakdown strength. Despite the numerous investigations of $Ta_2O_{5}$ material, there have little been established the clear understanding of the annealing effect on capacitance characteristic and conduction mechanism. This study presents the dielectric properties $Ta_2O_{5}$ MIM capacitor structure Processed by $O_2$ RTA oxidation. X-ray diffraction patterns showed the existence of amorphous phase in $600^{\circ}C$ annealing under the $O_2$ RTA and the formation of preferentially oriented-$Ta_2O_{5}$ in 650, $700^{\circ}C$ annealing and the AES depth profile showed $O_2$ RTA oxidation effect gives rise to the $O_2$ deficientd into the new layer. The leakage current density respectively, at 3~1l$\times$$10_{-2}$(kV/cm) were $10_{-3}$~$10_{-6}$(A/$\textrm{cm}^2$). In addition, behavior is stable irrespective of applied electric field. the frequency vs capacitance characteristic enhanced stability more then $Ta_2O_{5}$ thin films obtained by $O_2$ reactive sputtering. The capacitance vs voltage measurement that, Vfb(flat-band voltage) was increase dependance on the $O_2$ RTA oxidation temperature.

키워드

참고문헌

  1. J. A. Nielsen, C. P. Chien, F. Shi, 'Embedded Tantalum Pentoxide Thin Film Capacitor for Use in Power Electronic Application' 2000 International Conference on High-Density Interconnect and System Packing, Proceeding pp. 346, 2000
  2. H. S. Yang, Y. S. Choi and S. M. Cho, 'Preparation and Properties of $Ta_2O_5$ Film Capacitors Using $TiSi_2$ Bottom Electrode,'Journal of Electronic Materials, Vol. 28, no. 12, 1999 https://doi.org/10.1007/s11664-999-0132-9
  3. M. Kee, U. Mackens, R. Kiewitt, G. Greuel and C. Metzmacher, 'Ferroelectrical Thin Films for Integrated Passive Component', Phillps Journal of Research Vol. 51 no. 3, 1998
  4. V. Mikhelashvili, G. Eisenstein, 'Charactrisistics of MIS Capacitors based on ultilayer $TiO_2/Ta_2O_5$ structures', Microelectronics Reliability Vol. 40, pp. 657, 2000 https://doi.org/10.1016/S0026-2714(99)00304-2
  5. S. Zaima, T. Furuka, Y. Yasuda and M. Iida, 'Preparation and Properties of Ta2O5 films by LPCVD for ULSI Application', J. Electrochem. Soc. Vol. 137, pp.1297, 1990 https://doi.org/10.1149/1.2086651
  6. Susumu Shibata, 'Dielectric constant of $Ta_2O_5$ thin film deposited by RF sputtering', Elsevier Thin Solid Films, Vol. 277, pp. 1, 1996 https://doi.org/10.1016/0040-6090(95)08234-4
  7. S. Zaima, T. Furuta, Y. Yasuda and M. Iidda, 'Conduction Mechanism of Leakage Current in $Ta_2O_5$ films on Si Prepared by LPCVD', J. Electrochem. Soc., Vol. 137, no. 9, pp. 2876, 1990 https://doi.org/10.1149/1.2087091
  8. R. M. Fleming, D. V. Lang C.D. W. Jones, 'Defect dominate charge transport in amorphous $Ta_2O_5$ thin films', J. of Appl. Phys., Vol. 88, no. 2, pp. 850-862, 2000 https://doi.org/10.1063/1.373747
  9. 김인성, 이동윤, 송재성, 윤문수, 박정후, '$Ta_2O_5$ 커패시터 박막의 유전 특성과 열 안정성에 관한 연구', 대한전기학회논문지, 제 51C권, 5호, pp. 185, 2002. 5
  10. Shin-Ichiro Kimura, Yasushiro Nishioka, Akira Shintani and Kiichiro Mukai, 'Leakage-current in-crease in amorphous $Ta_2O_3$films due to pin-hole growth during annealing below $600^{\circ}C$', J. Electrochem. Soc. Vol. 130,, No. 129, pp. 2414, 1983 https://doi.org/10.1149/1.2119599
  11. Nishioka Y., Kimura, S. Shinnriki, 'Dielectric Characteristics of Double layer Structure of Extremely Thin $Ta_2O_5/SiO_2$ Films on Si', J. of Electrochem. Soc., Vol. 34, pp. 410-422, 1987 https://doi.org/10.1149/1.2100469
  12. S. Ezhilvalavan, Ming Shiahn Tsaia and Tseung Yuen Tseng 'Dielectric Relaxation and Analysis of $Ta_2O_5$ Thin films', J. Phys. D: Appl. Phys., Vol. 33 (200) pp. 1137, 2000 https://doi.org/10.1088/0022-3727/33/10/301
  13. A. G. revesz, J. H. Reynolds, and J. F. Allison, 'Optical Properties of Tantalum Oxide Films on Silicon', J. Electrochem. Soc., Vol. 123, no. 6, pp. 889, 1976 https://doi.org/10.1149/1.2132963
  14. Lewis E. Hollander, and Patricia L. Castro, 'Dielectric Properties of Single-Crystal Nonstoichipmetric Rutile $(TiO_2)$', J. Appl. Phy., Vol. 33, no. 12, pp. 3421, 1962 https://doi.org/10.1063/1.1702423
  15. P. C. Joshi and M. W. Cole, 'Influence of postdeposition annealing on the enhanced structural and electrical properties of amorphous and crystalliane $Ta_2O_5$ thin films for dynamic random access memory application', J. Appl. Phy., Vol. 86, no. 2, pp. 871, 1999 https://doi.org/10.1063/1.370817
  16. Gottlieb S. Oehrlein, Thin Solid Films, Vol. 156, pp. 207, 1988 https://doi.org/10.1016/0040-6090(88)90315-X
  17. H. Shinriki, M. Nakata, A. Nakao and S. Tachi, Extended Abstract of the 1991 International Conf. on Solid State Devices and Materials, pp. 198, 1991