@inproceedings{61ac5a1cad1346bf8a6ad9e94fa6ad17,
title = "Sulfonic acid based solutions for electrochemical mechanical removal of tantalum",
abstract = "Electrochemical mechanical planarization (ECMP) is being actively explored for removal and planarization of copper films. Development of a full sequence ECMP process would require the removal of the barrier layer as well. Chemical systems that exhibit a 1:1 selectivity between the barrier layer and copper would be ideal for the barrier removal step of ECMP. A fundamental study was undertaken to evaluate the usefulness of a sulfonic acid based chemical system for the removal of tantalum under ECMP conditions. Copper and tantalum samples were polished at low pressures (∼0.5 psi) under galvanostatic conditions in sulfonic acid based solutions maintained at different pH values. At a current density of 0.25 mA/cm2 and pH of 10, tantalum removal rate of ∼100 {\AA}/min with a 1:1 selectivity to copper has been obtained in 0.3M sulfonic acid solutions. The presence of a small amount (∼ 0.1%) of colloidal silica particles is required to obtain good removal rates.",
author = "A. Muthukumaran and N. Venkataraman and V. Lowalekar and S. Raghavan",
year = "2006",
language = "English (US)",
isbn = "9889884445",
series = "Semiconductor Technology, ISTC2007 - Proceedings of the 6th International Conference on Semiconductor Technology",
publisher = "Electrochemical Society",
pages = "282--289",
booktitle = "Semiconductor Technology, ISTC2007 - Proceedings of the 6th International Conference on Semiconductor Technology",
note = "6th International Conference on Semiconductor Technology, ISTC2007 ; Conference date: 18-03-2007 Through 20-03-2007",
}