Chemical Mechanical Polish of Potential New Barrier Material Ruthenium (Ru) in ULSI Copper Interconnects

Abstract:

Ruthenium (Ru) and ruthernium alloys may be utilized as new copper barrier materials in copper interconnects of ultra-large scale integration (ULSI), and chemical mechanical polish (CMP) can be applied in planarization for ULSI production. In this paper, CMP experiments were done on high purity Ru by using home-made slurry, the effect of oxidizer, complexing agent, polishing downforce, pH value, inhibitor species and inhibitor concentration on the material removal rate (MRR) was investigated. The results revealed that MRR can reach 8.7 nm/min under the following conditions: the main constituents in slurry were 1 wt.% SiO2, 1 wt.% (NH4)2S2O8, 1 wt.% tartaric acid and 3 mM imidazole, the pH value was 8.0, the down force was 2.5 psi (17.24 kPa); the roughness Ra was 7.6 nm under these conditions.

• Periodical: Key Engineering Materials (Volume 499)
• Pages: 33-38
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.499.33
• Online since: January 2012
• Authors: Xiang Feng Chu, X.J. Li, Y.P. Dong, H.B. Qiao, L.S. Bai
• Keywords: CMP, Removal Rate, Ruthenium

References

[1] C. J. Chang and C. M. Chieh: Thin Solid Films Vol. 335 (1998), p.146.

[2] W. L. Yang, W. F. Wu, D. G. Liu and et al.: Solid-State Electron Vol. 45 (2001), p.149.

[3] Q. Xie, X. P. Qu, J. J. Tan and et al.: Applied Surface Science Vol. 253(2006), p.1666.

[4] J. P. Jacquemin, E. Labonne, C. Yalicheff and et al.: Microelectronic Engineering Vol. 82(2005), p.613.

[5] C.C. Yang, T. Spooner, S. Ponoth and et al.: Proc. Int. Interconnect Tech. Conf. (2006), p.187.

[6] D. C. Perng, J. B. Yeh and K. C. Hsu: Applied Surface Science Vol. 254 (2008), p.6059.

[7] B. H. Choi, Y. H. Lim, J. H. Lee and et al.: Microelectronic Engineering Vol. 87 (2010), p.1391.

[8] Q. Xie, Y. L. Jiang, J. Musschoot and et al.: Thin Solid Films Vol. 517 (2009), p.4689.

[9] J. Li, H. S. Lu, Y. W. Wang and et al.: Microelectronic Engineering Vol. 88 (2011), p . 635.

[10] D. C. Perng, K. C. Hsu, S. W. Tsai and et al.: Microelectronic Engineering Vol. 87 (2010), p.365.

[11] V. R. K. Gorantla, S. B. Emery, S. Pandija and et al.: Materials Letters Vol. 59 (2005), p.690.

[12] Y. N. Prasad and S. Ramanathan: Electrochimica Acta Vol. 52 (2007), p.6353.

[13] J. Y. Jeong and W. G. Lee: Electrochemical and Solid-State Letters Vol. 6 (2003), p.45.

[14] L. L. Chapelon, H. Chaabouni, G. Imbert and et al.: Microelectronic Engineering Vol. 85 (2008), p. (2098).

[15] W. J. Lee and H. S. Park: Applied Surface Science Vol. 228 (2004), p.410.

[16] I. K. Kim, Y. J. Kang, T. Y. Kwon and et al.: Electrochemical and Solid-State Letters Vol. 11(6) (2008), p.150.

[17] K. Qin, B. Moudgil and C. W. Park: Thin Solid Films Vol. 446 (2004), p.277.

[18] T. Du and V. Desal: Journal of Materials Science Letters Vol. 22 (2003), p.1623.

[19] L. Wang, K. Zhang, Z. Song, and S. Feng: Applied Surface Science Vol. 253 (2007), p.4951.