Sulfonic acid based solutions for electrochemical mechanical removal of tantalum

A. Muthukumaran, N. Venkataraman, V. Lowalekar, S. Raghavan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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/cm 2 and pH of 10, tantalum removal rate of ∼100 Å/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.

Original languageEnglish (US)
Title of host publicationSemiconductor Technology, ISTC2007 - Proceedings of the 6th International Conference on Semiconductor Technology
Pages282-289
Number of pages8
StatePublished - Dec 1 2006
Event6th International Conference on Semiconductor Technology, ISTC2007 - Shanghai, China
Duration: Mar 18 2007Mar 20 2007

Publication series

NameSemiconductor Technology, ISTC2007 - Proceedings of the 6th International Conference on Semiconductor Technology

Other

Other6th International Conference on Semiconductor Technology, ISTC2007
CountryChina
CityShanghai
Period3/18/073/20/07

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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