Dual reduced agents for barrier removal in chemical mechanical polishing

#1. Field of the Invention

#Aspects of the invention relate generally to chemical mechanical polishing and planarization of semiconductor devices and to methods and compositions for removing a barrier layer material by chemical mechanical polishing techniques.

#2. Description of the Related Art

#So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.

#It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

#FIG. 1 is a schematic view of a substrate illustrating seam damage;

#In general, aspects of the invention provide compositions and methods for planarizing a substrate surface with reduced or minimal residue remaining from a polishing process. The invention will be described below in reference to a planarizing process for the removal of residues of excess conductive materials, such as barrier layer materials, from a substrate surface by chemical mechanical planarization, or chemical mechanical polishing (CMP) technique. Chemical mechanical polishing is broadly defined herein as polishing a substrate by chemical activity, mechanical activity, or a combination of both chemical and mechanical activity.

#Residual material is broadly defined as any excess conductive material remaining after one or more polishing process steps. Residual materials may include tantalum containing materials, such as tantalum, tantalum nitride or tantalum alloys, such as tantalum silicon nitride, as well as by-products of reacted materials on or from the substrate surface. Residual conductive material may partially or completely cover the surface a substrate. For example, residual material may cover about 25% or less of the surface area of the substrate. Residual material is generally present in an amount covering between about 5% and about 10% of the surface area of a substrate after one or more polishing process steps. Alternatively, residual material does contemplate covering the complete surface area of a substrate up to about 1000 Å thick.

#One apparatus for performing the planarizing process and composition described herein is a Mirra® CMP System available from Applied Materials, Inc., as shown and described in U.S. Pat. No. 5,738,574, entitled, “Continuous Processing System for Chemical Mechanical Polishing,” the entirety of which is incorporated herein by reference. Although, the CMP process and composition is illustrated utilizing the Mirra® CMP System, any system enabling chemical mechanical polishing using the composition described herein can be used to advantage.