Effect of Cerium Ammonium Nitrate and Alumina Abrasive Particles on Polishing Behavior in Ruthenium Chemical Mechanical Planarization

Ruthenium CMP에서 Cerium Ammonium Nitrate와 알루미나 연마 입자가 연마 거동에 미치는 영향

  • 이상호 (한양대학교 금속재료공학과) ;
  • 이승호 (한양대학교 금속재료공학과) ;
  • 강영재 (한양대학교 금속재료공학과) ;
  • 김인권 (한양대학교 금속재료공학과) ;
  • 박진구 (한양대학교 금속재료공학과)
  • Published : 2005.09.01


Cerium ammonium nitrate (CAN) and nitric acid was used an etchant and an additive for Ru etching and polishing. pH and Eh values of the CAN and nitric acid added chemical solution satisfied the Ru etching condition. The etch rate increased linearly as the concentration of CAN increased. Nitric acid added solution had the high etch rate. But micro roughness of etched surfaces was not changed before and after etching, The removal rate of Ru film was the highest in $1wt\%$ abrasive added slurry, and not increased despite the concentration of alumina abrasive increased to $5wt\%$. Even Ru film was polished by only CAN solution due to the friction. The highest removal rate of 120nm/min was obtained in 1 M nitric acid and $1wt\%$ alumina abrasive particles added slurry. The lowest micro roughness value was observed in this slurry after polishing. From the XPS analysis of etched Ru surface, oxide layer was founded on the etched Ru surface. Therefore, Ru was polished by chemical etching of CAN solution and oxide layer abrasion by abrasive particles. From the result of removal rate without abrasive particle, the etching of CAN solution is more dominant to the Ru CMP.


  1. C. Y. Chang and S. M. Sze, 'ULSI Technology', McGraw-Hill, Intl. ed., p. 2, 1996
  2. Y. Kawamoto and T. Kaqa, 'A 128 $um^2$ bit-line shielded memory cell technology for 64 Mb DRAM', Proc. the Symp. on VLSI Technol., p. 13, 1990
  3. T. Ema, S. Kawanago, and T. Nishida, '3-dimensional Stacked Capacitor cell for 16 M and 64 M DRAM's', IEDM Tech Dig, p. 592, 1988
  4. M. Ino, J. Miyano, PI. Kurogi, H. Tamura, Y. Nagatomo, and M. Yoshimaru, 'Rugged surface polycrystalline silicon film deposition and its application in a stacked dynamic random access memory capacitor electrode', J. Vac. Sci. Technol. B, Vol. 14, Iss. 2, p. 751, 1996
  5. C. H. Liu, S. J. Chang, J. F. Chen, S. C. Chen, J. S. Lee, and U. H. Liaw, 'High-quality ultrathin chemical-vapor-deposited $Ta_2O_5$ capacitors prepared by high-density plasma annealing', Mat. Sci. and Eng. B, Vol. 106, Iss. 3, p. 234, 2004
  6. H. J. Kim, J. S. Song, I. S. Kim, and S. S. Kim, 'Electrical characteristics of Ti-O/$Ta_2O_5$ thin film sputtered on Ta/Ti/$Al_O_3$ substrate', Thin Solid Films, Vol. 446, Iss. 1, p. 124, 2004
  7. R. A. McKee, F. J. Walker, and M. F. Chisholm, 'Physical structure and inversion charge at a semiconductor interface with a crystalline oxide', Science, Vol. 293, Iss. 5529, p. 468, 2001
  8. A. Kumar and S. G. Manavalan, 'Characterization of barium strontium titanate thin films for tunable microwave and DRAM applications', Surf. and Coat. Technol., Vol. 198, Iss. 1-3, p. 406, 2005
  9. T. Kuroiwa, Y. Tsunemine, T. Horikawa, T. Makita, J. Tanimural, N. Mikami, and K. Sato, 'Dielectric properties of ($Ba_xSr_{1-x}$) $TiO_3$ thin films prepared by RF sputtering for dynamic random access memory application', Jpn. J. Appl. Phys., Vol. 33, No. 9B, p. 5187, 1994
  10. K. Kishiro, N. Inoue, S.-C. Chen, and M. Yoshimaru, 'Structure and electrical properties of thin $Ta_2O_5$ deposited on metal electrodes', Jpn. J. Appl. Phys., Vol. 37, No. 3B, p. 1336, 1998
  11. Ch. Wenger, R. Sorge, T. Schroeder, A. U. Mane, G. Lippert, G. Lupina, J. Dabrowski, P. Zaumseil, and H. -J. Muessig, 'MIM capacitors using amorphous high-k $PrTi_xO_y$ dielectrics', Microelectronic Eng., Vol. 80, p. 313, 2005
  12. S. J. So, D. S. Oh, H. K. Sung, and C. B. Park, 'Fabrication of MIM capacitors with 1000 ${\AA}$ silicon nitride layer deposited by PECVD for InGaP/GaAs HBT applications', J. Crystal Growth, Vol. 279, Iss. 3-4, p. 341, 2005
  13. T. H. Perng, C. H. Chien, C. W. Chen, P. Lehnen, and C. Y. Chang, 'High-density MIM capacitors with $HfO_2$ dielectrics', Thin Solid Films, Vol. 469-470, p. 345, 2004
  14. B. S. Ju and H. W. Kim, 'A concave-type structure of a Ru electrode capacitor fabricated by the reactive ion etching method', Microelectronic Eng., Vol. 70, Iss. 1, p. 30, 2003
  15. H. W. Kim, B. S. Ju, and C. J. Kang, 'Investigation into the patterning of a concave-type Pt electrode capacitor using the reactive ion etching method', Microelectronic Eng., Vol. 65, Iss. 4, p. 489, 2003
  16. W. J. Lee and H. S. Park, 'Development of novel process for Ru CMP using ceric ammonium nitrate (CAN) containing nitric acid', Appl. Surf. Sci., Vol. 228, Iss. 1-4, p. 410, 2004
  17. 김상용, 서용진, 김태형, 이우선, 김창일, 장의구, 'Chemical mechanical polishing (CMP) 공정을 이용한 multilevel metal 구조의 광역평탕화에 관한 연구,' 전기전자재료학회논문지, 11권, 12호, p. 1084, 1998
  18. 이우선, 고필주, 김남훈, 서용진, '산화제 첨가에 따른 $WO_3$ 박막의 CMP 평탄화 특성,' 전기전자재료학회논문지, 18권, 1호, p. 12, 2005
  19. M. Pourbaix, 'Atlas of electochemical equilibria in aqueous solutions', N. A. C. E. Intl., Houston, TX., p. 346, 1974
  20. F. Kaufman, D. B. Thompson, R. E. Boradie, M. A. Jaso, W. L. Guthrie, D. J. Peason, and M. B. Small, 'Chemical mechanical polishing for fabricating W metal features as chip interconnects', J. Electrochem. Soc, Vol. 138, No. 11, p. 3460, 1991