DOI QR코드

DOI QR Code

Electrochemical Corrosion and Chemical Mechanical Polishing(CMP) Characteristics of Tungsten Film using Mixed Oxidizer

혼합 산화제를 사용한 텅스텐 막의 전기화학적 부식 및 CMP 특성

  • 나은영 (조선대학교 에너지자원 신기술연구소) ;
  • 서용진 (대불대학교 전기공학과) ;
  • 이우선 (조선대학교 전기공학과)
  • Published : 2005.04.01

Abstract

In this paper, the effects of oxidants on tungsten chemical mechanical polishing (CMP) process were investigated using three different oxidizers such as Fe(NO₃)₃, KIO₃ and H₂O₂. Moreover, the interaction between the tungsten film and the oxidizer was discussed by potentiodynamic polarization measurement with three different oxidizers, in order to compare the effects of W-CMP and electrochemical characteristics on the tungsten film as a function of oxidizer. As an experimental result, the tungsten removal rate reached a maximum at 5 wt% Fe(NO₃)₃concentration, and when 5 wt% H₂O₂was added in the slurry, the removal rate of W increased. Also, the microstructures of surface layer by atomic force microscopy(AFM) image were greatly influenced by the slurry chemical composition of oxidizers. It was shown that the surface roughness and removal rate of the polished surface were improved in Fe(NO₃)₃than KIO₃. The electrochemical results indicate that the corrosion current density of the 5 wt% H₂O₂ and 5 wt% H₂O/sub 2+/+ 5 wt% Fe(NO₃)₃was higher than the other oxidizers. Therefore, we conclude that the W-CMP characteristics are strongly dependent on the kinds of oxidizers and the amounts of oxidizer additive.

Keywords

References

  1. W. S. Lee, S. Y. Kim, Y. J. Seo, and J. K. Lee, 'An optimization of tungsten plug chemical mechanical polishing(CMP) using different consumables', J. Mater. Sci.: Mater. Electron., Vol. 12, No. 1, p. 63, 2001
  2. W. J. Patrick, W. L. Guthrie, C. L. Standley, and P. M. Schiable 'Application of chemical mechanical polishing to the fabrication of VLSI circuit interconnection', J. Electrochem. Soc., Vol. 138, No. 6, p.1778, 1991
  3. 김상용, 서용진, 김태형, 이우선, 김창일, 장의구, 'Chemical mechanical polishing 공정을 이용한 multilevel metal 구조의 광역평탄화에 관한 연구', 전기전자재료학회논문지,11권, 12호, p. 1084, 1998
  4. D. Tamboli, S. Seal, V. Desai, and A. Maury, 'Studies on passivation behavior of tungsten in application to chemical mechanical polishing', J. Vac. Sci. Technol., Vol. 17, No. 4, p. 1168, 1999
  5. V. S. Chathapuram, T. Du, K. B. Sundaram, and V. Desai, 'Role of oxidizer on the chemical mechanical panarization of Ti/TiN barrier layer', Microelectron. Eng., Vol. 65, No. 4, p. 478, 2003
  6. M. Bielmann, U. Mahajan, R. K. Singh, D. O. Shah, and B. J. Palla 'Enhanced tungsten chemical mechanical polishing using stable alumina slurries', Electrochem. Solid-state Letters, Vol. 2, No.3, p. 148, 1999
  7. Y. J. Seo and W. S. Lee, 'Effects of oxidant additives for exact selectivity control of W-and Ti-CMP process', Microelectron. Eng., Vol. 77, No. 2, p. 132, 2005
  8. S. Y. Kim, Y. J. Seo, W. S. Lee, and E. G. Chang, 'Study of micro-defect on oxide CMP in VLSI circuits', Electrochem, Soc., Proc., Vol. 99, p, 275, 1999
  9. J. Henandez, P. Wrschka, and G. S. Oehrlein, 'Surface chemistry studies of copper chemical mechanical planarization', J. Electrochem. Soc, Vol. 148, No. 7, p. G359, 2001