Chemical mechanical polishing slurries and cleaners containing salicylic acid as a corrosion inhibitor

Abstract

The invention provides methods for CMP polishing, residue removal and post-CMP polishing of a metal containing substrate. The CMP polishing methods for contacting a metal-containing substrate with a composition comprising an oxider, a salicylic acid compound, water, and an abrasive. The post-CMP polishing and residue removal methods require contacting a metal-containing substrate with a composition comprising an oxidizer, a salicylic acid compound, and water.

Description

FIELD OF THE INVENTION [0001] The invention relates to compositions and methods for chemical-mechanical polishing / planarization and / or post-CMP cleaning of metal-containing substrates with a composition containing an oxidizer and an organic or inorganic acid, and more particularly to compositions and methods for chemical-mechanical polishing / planarization and / or post-CMP cleaning of copper-containing substrates used in integrated circuit manufacture. BACKGROUND OF THE INVENTION [0002] Chemical-mechanical polishing or planarization (CMP) processes are well-known. See, for example, Chemical Mechanical Polishing in Silicon Processing, Semiconductors and Semimetals, Vol. 62, Edited by Li, S. et al., which is expressly incorporated herein by reference. Also directly incorporated by reference for all purposes are the following commonly assigned patents: [0003] U.S. Pat. No. 5,891,205 to Picardi et al., which issued on Apr. 6, 1999, entitled Chemical Mechanical Polishing Composition; [0004...

AI Technical Summary

Benefits of technology

[0040] The invention provides a method for chemically polishing mechanically polishing a metal-containing substrate comprising contacting a metal-containing substrate with a composition comprising: an oxidizing agent; between about 0.0001 M to about 1 M of a salicylic acid compound, wherein the salicylic acid compound is present in an amount sufficient to substantially inhibit corrosion and water, at a temperature and for a time sufficient to chemically mechanically polish the metal-containing substrate.

Problems solved by technology

This approach is generally disfavored as the requisite downward pressure is considered too high and too likely to cause wafer damage, such as scratching, delamination, or destruction of material layers on the wafer.

When the wafer is fragile, as is generally the case with substrates layered with films such as porous films having a low dielectric constant, these damage issues are particularly acute and detrimental in terms of wafer yield and performance.

Generally, faster chemical-mechanical polishing results in more defects.

These approaches are generally undesirable, as they typically complicate CMP in terms of tooling and process control for example, consume more process time, and / or increase costs.

When an oxidizer and chelator are used in combination, excessive corrosion of the substrate may result.

Addition of such corrosion inhibitors can be cumbersome often requiring a specialized method.

Furthermore, the chemistry of CMP compositions may limit the group of suitable corrosion inhibitors.

This approach is largely disfavored as the use of increased amounts of oxidizing agents increase material costs and also detrimentally add to the handling issues and environmental issues associated with many oxidizing agents and also increase costs.

It is generally known that oxidizers admixed in a solution can provide synergistic etching rates.

While ferric salts, cerium salts, peroxides, persulfates, or hydroxylamines form the oxidizing capacity of most commercially available CMP slurries, those of ordinary skill in the art have long known that these oxidizers can be admixed with others in this group and also with other oxidizers, and the resulting composition can show synergistic results.

Certain metals, such as those with a tendency to plate on or be absorbed on to at least one part of the substrate, are more damaging than other metals.

There have been various “post-polishing cleaners” developed to remove metallic contamination, but removal of all undesired metal ions is substantially beyond the range of cleaners, and as the size of the structures continues to decrease, even a very small number of metallic atoms deposited on a surface will result in undesired shorts or current leakage.

Additionally, metal ion-containing fluids are often environmentally undesirable and expensive treatment may be needed prior to waste disposal of used product.

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