Skip to main content Accessibility help
×
Home

Fundamental Studies on the Mechanisms of Oxide CMP

  • Uday Mahajan (a1), Seung-Mahn Lee (a1) and Rajiv K. Singh (a1)

Abstract

In this paper, results of studies on the addition of salt to a polishing slurry, in terms of its effect on slurry stability, SiO2 polishing rate and surface roughness of the polished surface are presented. Three salts, viz. LiCl, NaCl and KCl were selected, and three concentrations were tested. Polishing rate measurements using these slurries show that adding salt leads to increased removal rate without affecting surface roughness significantly. Based on these results, we can say that the agglomerates formed by adding salt to the slurry are fairly soft and easily broken during the polishing process. In addition, turbidity and particle size measurements show that significant coagulation of the particles in the slurry occurs only at the highest salt concentration, and is fastest for LiCl and NaCl, with KCl showing the slowest coagulation. From these results, it can be concluded that the enhancement in polish rate is due to increased contact at the wafer-pad-slurry interface, and not due to formation of larger agglomerated particles in the slurry. This is because of reduced electrostatic repulsion between these three surfaces, due to the screening of their negative surface charge by the metal ions in solution, resulting in a higher wear rate.

Copyright

References

Hide All
1. Steigerwald, J.M., Murarka, S.P. and Gutmann, R.J., Chemical Mechanical Planarization of Microelectronic Materials, John Wiley & Sons, New York (1997)10.1002/9783527617746
2. Cook, L.M., J. Non-cryst. Solids 120, 152 (1990)10.1016/0022-3093(90)90200-6
3. Hunter, R.J., Introduction to Modern Colloid Science, Oxford University Press, New York (1993)
4. O, R.W. Brien, Cannon, D.W. and Rowlands, W.N., J. Colloid Interface Sci. 173, 406 (1995)
5. Bielmann, M., Mahajan, U., Singh, R.K., Shah, D.O. and Palla, B.J., Electrochem. Solid State Lett. 2 (3), 148 (1999)10.1149/1.1390765
6. Bielmann, M., U. Mahajan and Singh, R.K., Electrochem. Solid State Lett. 2 (8), 401 (1999)10.1149/1.1390851
7. Colic, M., Fisher, M.L. and Franks, G.V., Langmuir 14, 6107 (1998)10.1021/la980489y
8. Mahajan, U., Bielmann, M. and Singh, R.K., Electrochem. Solid State Lett. 2 (2), 80 (1999)10.1149/1.1390741
9. Iler, R., The Chemistry of Silica, John Wiley and Sons, New York (1979)

Fundamental Studies on the Mechanisms of Oxide CMP

  • Uday Mahajan (a1), Seung-Mahn Lee (a1) and Rajiv K. Singh (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.