CMP Cleaning Composition With Corrosion Inhibitor for Copper-Cobalt Surfaces
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Solution Overview
Problem
Existing cleaning compositions for microelectronic device substrates are ineffective in removing residue while preventing corrosion of metal features, particularly copper and cobalt, which are crucial for high-performance integrated circuits.
Innovation Solution
Aqueous cleaning compositions containing non-aqueous ingredients such as bases (e.g., choline hydroxide, tetraethylammonium hydroxide), cleaning compounds (e.g., alkanol amines), and corrosion inhibitors (e.g., guanidine functional additives) are used to effectively remove residue while minimizing metal corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If strong cleaning agents are used to remove residue, then cleaning efficiency is improved, but corrosion of metal features increases
Solution Approach 1:
A corrosion inhibitor is introduced as an intermediary substance that mediates between the cleaning composition and metal features. The inhibitor forms a protective layer on metal surfaces, preventing direct contact between corrosive cleaning agents and metal, thereby enabling effective residue removal without damaging copper, cobalt, or other metal interconnects
Solution Approach 2:
The cleaning composition is formulated as a composite system containing multiple components: base cleaning agents for residue removal, corrosion inhibitors for metal protection, and buffering agents for pH control. This composite formulation allows the composition to simultaneously achieve strong cleaning power while maintaining compatibility with sensitive metal features through the synergistic interaction of its components
2Productivity
If pH is increased to improve cleaning performance, then residue removal is enhanced, but metal corrosion is accelerated
Solution Approach 1:
The pH of the cleaning composition is optimized to a specific range (pH 9-11) that balances cleaning effectiveness with metal compatibility. Buffering agents are incorporated to maintain pH within this optimal range, preventing excessive alkalinity that would cause metal corrosion while ensuring sufficient cleaning power for residue removal
Solution Approach 2:
Corrosion inhibitors serve as protective intermediaries that allow the use of higher pH cleaning agents without compromising metal integrity. These inhibitors form protective films on metal surfaces, enabling the cleaning composition to operate at elevated pH levels for improved cleaning performance while the inhibitor prevents the harmful effects of high pH on metal features
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The compositions achieve high residue removal efficiency (>70%) with minimal corrosion of copper and cobalt surfaces, ensuring the integrity and reliability of microelectronic devices.
Implementation Method 1
The corrosion inhibitor is effective to reduce an amount of corrosion of the metal
Implementation Method 2
chemical materials that interact chemically with materials of the surface to facilitate selective removal of certain material from the surface
Data Source
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Figure 3~4
AI summary
A cleaning composition and process for cleaning an in-process microelectronic device substrate, e.g., by post-chemical mechanical polishing (CMP) cleaning, to remove residue from a surface thereof, wherein the cleaning composition may be especially effective for cleaning a substrate surface that includes exposed metal such as cobalt, copper, or both, along with dielectric or low k dielectric material, and wherein the cleaning composition includes corrosion inhibitor to inhibit corrosion of the exposed metal.