Method and composition for selectively removing metal hardmask and other residues from semiconductor device substrates comprising low-k dielectric material and copper

Abstract

An aqueous removal composition having a pH in the range of from 2 to 14 and method for selectively removing an etching mask consisting essentially of TiN, TaN, TiNxOy, TiW, W, or alloy of Ti or W relative to low-k materials from a semiconductor substrate comprising said low-k materials having a TiN, TaN, TiNxOy, TiW, W, or alloy of Ti or W etching mask thereon wherein the removal composition comprises at least one oxidizing agent and a carboxylate compound.

Description

CROSS REFERENCE TO RELATED APPLICATIONS / INCORPORATION BY REFERENCE STATEMENT[0001]This application claims the benefit of U.S. provisional application Ser. No. 61 / 889,968, filed Oct. 11, 2013, the entire contents of which are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The presently disclosed and claimed inventive concept(s) relates to compositions and methods for selectively removing metal hardmask and other residues from integrated circuit (IC) device substrates, and, more particularly, to compositions and methods useful for selectively removing TiN, TaN, TiNxOy, TiW, and W metal hardmask, and metal hardmasks comprising alloys of the foregoing, as well as other residues from such substrates comprising low-k dielectric materials, TEOS, copper, cobalt and other low-k dielectric materials, using carboxylate compounds.[0003]Devices with critical dimensions on the order of 90 nanometers (nm) have involved integration of copper conductors and low-k dielectric...

AI Technical Summary

Benefits of technology

This patent describes an improved semiconductor processing composition that can remove metal hardmask from a dual damascene structure without damaging wiring metallurgy and dielectric materials. The composition contains carboxylate compounds that have a high selectivity for removing metal hardmask, photoresist, polymeric materials, and copper oxide from via and trench surfaces without damaging underlying layers that form the structure. Among the carboxylate compounds that exhibit excellent results are ammonium carboxylates, such as ammonium oxalate, ammonium lactate, ammonium tartrate, ammonium citrate tribasic, ammonium acetate, ammonium carbamate, ammonium carbonate, ammonium benzoate, tetraammonium EDTA, ethylenediaminetetraacetic acid diammonium salt, ammonium succinate, ammonium formate, ammonium 1-H-pyrazole-3-carboxylate, and mixtures thereof. The removal composition has an inherently high etch rate for titanium nitride, tantalum nitride, titanium nitridexoxide, titanium dioxide, tungsten, and alloy of copper and tungsten (e.g., alloy of copper and tungsten) with reduced oxidizer decomposition rate and extended bath life. The composition has a low processing temperature and can decrease device processing time and increase throughput.

Problems solved by technology

As the technology nodes advance to 45 nm and smaller, the decreasing size of the semiconductor devices makes achieving critical profile control of vias and trenches more challenging.

Fabrication of advanced generation devices that require copper conductors and low-k dielectric materials (typically carbon-doped silicon oxide (SiOCH), or porous low-k materials) give rise to the problem that both materials can react with and be damaged by various classes of prior art cleaners.

Low-k dielectrics, in particular, may be damaged in the cleaning process as evidenced by etching, changes in porosity / size, and ultimately changes in dielectric properties.

Some residues may be cleaned in a very short period of time, while some residues require much longer cleaning procedures.

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