Methods of post chemical mechanical polishing and wafer cleaning using amidoxime compositions

Abstract

The invention relates to a method for the removal of residues and contaminants from metal or dielectric surfaces and to a method for chemical mechanical polishing of a copper or aluminum surface. The methods of the invention include using an aqueous amidoxime complex agent. Optionally, the pH of the solution can be adjusted with an acid or base. The method includes applying the above composition to the copper or aluminum surface and polishing the surface in the presence of the composition.

Description

CROSS-REFERENCE TO ELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 000,727, filed Oct. 29, 2007, and U.S. Provisional Application No. 61 / 006,225, filed Dec. 31, 2007, both of which are incorporated herein by reference in their entirety.BACKGROUND OF THE INVENTION[0002]The present invention relates to compositions and methods for removal of chemical residues from metal or dielectric surfaces or for chemical mechanical polishing of a copper or aluminum surface including an aqueous solution comprising an amidoxime complex applied for a time sufficient to remove the chemical residues.[0003]The National Technology Roadmap for the Semiconductor Industries (1994) indicated that the current computer chips with 0.35 micron feature sizes will be reduced to 0.18 micron feature size in 2001. The DRAM chip will have a memory of 1 gigabit, and typical CPU will have 13 million transistors per cm2 (currently they only contain about 4 million). The...

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Benefits of technology

[0018]The present invention provides a method of solving one or more of the following problems common with prior art compositions and methods: reducing or elimina

Problems solved by technology

This length of wire would severely compromise the chip's speed performance without design changes.

Corrosion of the metal surfaces results in metal recess and thinning of the metal lines.

However, these references suffer from one or more of the disadvantages discussed below.

Any oxidation or corrosion on the surface or recess of the metal causes thinning of the lines (dissolution) and results in poor performance or failure of the semiconductor device.

Many cleaning solutions available in the art do not provide a film forming agent, and thus suffer from a high static etch rate and/or high RMS value.

Some existing acidic cleaning chemistries do not passivate the metal, resulting in corrosion during and after the cleaning step by oxidation of the metal surface.

Some rinsing agents can leave deposits on the surface of the work-piece, thus contaminating the wafer.

Adding a second step is also a drawback due to the fact that it lengthens the manufacturing process, complicates the process by having to handle more chemicals and more steps, and provides one more possible source of contamination or other quality control problems.

These complexing chemicals are re

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