Chemical Mechanical Polishing Characteristics of PZT Thin Films

PZT 박막의 화학.기계적 연마 특성

  • Published : 2006.12.01

Abstract

In this paper we first applied the chemical mechanical polishing (CMP) process to the planarization of ferroelectric film in order to obtain a good planarity between electrode and ferroelectric film. $Pb_{1.1}(Zr_{0.52}Ti_{0.48})O_3$ (shortly PZT) ferroelectric film was fabricated by the sol-gel method. And then, we compared the structural characteristics before and after CMP process of PZT films. Removal rate, WIWNU% and surface roughness have been found to depend on slurry abrasive types and their hardness, especially, surface roughness and planarity were strongly depends on its pH value. A maximum in the removal rate is observed in the silica slurry, in contrast with the minimum removal rate occurs at ceria slurry. We found that the surface roughness of PZT films can be significantly reduced using the CMP technique.

Keywords

References

  1. Y. Igarashi, K. Tani, M. Kasai, K. Ashkaga and T. Ito, 'Submicron Ferroelectric Capacitors Fabricated by Chemical Mechanical Polishing for High-Density Ferroelectric Memories', Jpn. J. Appl, Phys. Vol.39, p.2083, 2000 https://doi.org/10.1143/JJAP.39.2083
  2. Takeharn, Jpn. J. Appl. phys. Vol.33, p.5190, 1994
  3. Basavaraj Angadi, Thin Solid Films, Vol.434, p.40, 2003 https://doi.org/10.1016/S0040-6090(03)00448-6
  4. P. Vitanov, A. Harizanova, T. Ivannova, D. Velkov, Zd. Raytcheva, 'Deposition, structure evolution and dielecrtrc properties of $BaTi0_3$ and $Ba_{x}Sr_{1-x}TiO_3$ thin films prepared by the sol-gel method', Vacuum, Vol. 69, Issues 1-3, pp.371-377, 2002.12 https://doi.org/10.1016/S0042-207X(02)00361-5
  5. Yong-Jin Seo and Sang-Yong Kim, 'Effects of Various Facility Factors on Chemical Mechanical Polishing Process defects', Japanese Journal of Applied Physics, Vol.41, No.11A, pp.6310-6312, 2002.11 https://doi.org/10.1143/JJAP.41.6310
  6. Woo-Sun Lee, Sang-Yong Kim, Yong-Jin Seo, Jong-Kook Lee, 'An Optimization of Tungsten Plug Chemical Mechanical Polishing (CMP) using Different Consumables', Journal of Materials Science Materials in Electronics, Kluwer Academic Publishers, Vol.l2, No.1, pp.63-68, 2001.01 https://doi.org/10.1023/A:1011276830620
  7. F. B. Kaufman, D. B. Thompson, R. E. Broadie, M. A. Iaso, W. L. Guthrie, D. J. Pearsonand M. B. Small, Electrochem. Soc., Vol.138, p.3460 (1991) https://doi.org/10.1149/1.2085434
  8. Sang-Yong Kim, So-Young Jeong, and Yong-Jin Seo, 'Effects of deionized water pressure and purified nitrogen gas on the chemical mechanical polishing process', Journal of Materials Science : Materials In Electronics, Kluwer Academic Publishers, Vol.13, No.5, pp.299-302, 2002.05 https://doi.org/10.1023/A:1015524009343
  9. Yong-Jin Seo, Sang-Yong Kim, Jin-Seong Park, and Woo-Sun Lee, 'Analysis of defect density according to the slurry filter size in the chemical mechanical polishing process', Journal of Korean Physics Society (JKPS), Vol.43, No.5, pp.798-801, 2003.11
  10. Yong-Jin Seo, Sung-Woo Park, Chul-Bok Kim, Sang -Yong Kim, Woo-Sun Lee, and Jinseong Park, 'Global Planarization Comparisons of STI-CMP Process with and without Reverse Moat Step', J. of Korean Physics Society (JKPS), Vol.42, No.92, pp.S421-S424, 2003.02
  11. K. T. Kim and C. I. Kim, 'Structure and dielectric properties of Bi-doped $Ba_{0.6}Sr_{0.4}TiO_3$ thin films fabricated by sol-gel methods,' Microelectronic Engineering, Vol.66, p.835, 2003. https://doi.org/10.1016/S0167-9317(02)01008-0
  12. J. K. Kim and H. J. Chang, J. Korean Phys. Soc. Vol.39, p.S232, 200l
  13. 서용진, 박성우, '졸겔법에 의해 제작된 강유전체 BST막의 기계화학적인 연마 특성', 대한전기학회 논문지, 제53C권 제3호, pp.128-132, 2004
  14. 서용진, 고필주, 박성우, 이강연, 이우선, '고집적 메모리 커패시터의 Vertical Sidewall Patterning을 위한 BTO 박막의 CMP 특성', 대한전기학회 논문지, 제55C권 제3호, pp.116-121, 2006
  15. 서용진, 이우선 '$BaTiO_3$$TiO_2$ 분말이 혼합된 연마제 슬러리(MAS)를 사용한 BTO 박막의 CMP 특성' 대한전기학회 논문지, 제55C권 제6호, pp. 291-296, 2006