Post-CMP Cleaning Composition for Copper-Safe Residue Removal
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Solution Overview
Problem
Existing cleaning compositions for microelectronic device substrates after chemical-mechanical processing (CMP) steps are inadequate in effectively removing residues without damaging the substrate's functional features, particularly with the emergence of copper-based interconnects, which require precise and residue-free cleaning to maintain device performance and reliability.
Innovation Solution
A composition comprising water, a chelating agent such as multifunctional alcohol poly(oxypropylene)polyamine, and a pH adjustor, along with optional additives, is used to remove residues from microelectronic device substrates, ensuring minimal damage to the substrate's features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cleaning compositions are used to remove residues after CMP, then cleaning efficiency is improved, but damage to copper-based interconnects and dielectric materials occurs
Solution Approach 1:
The cleaning composition uses specific parameter ranges: pH 2-4 (acidic but controlled), hydrogen peroxide concentration of 0.1-5%, and chelating agent concentrations of 0.01-5%. These parameter changes create a balanced chemical environment that enables effective residue removal while preventing excessive etching or damage to copper interconnects and dielectric materials.
Solution Approach 2:
The invention employs a composite cleaning composition containing multiple components working synergistically: hydrogen peroxide (oxidizing agent), chelating agents (for metal ion complexation), and buffer agents (for pH control). This composite formulation achieves both high cleaning efficiency and selectivity to protect sensitive substrate features.
2Manufacturing precision
If strong cleaning agents are used to remove all residues, then manufacturing precision is improved, but corrosion of copper interconnects occurs
Solution Approach 1:
Chelating agents serve as intermediaries that selectively bind to metal ions (including copper) through coordination chemistry. This intermediary action allows the cleaning composition to remove metal-containing residues without directly attacking or corroding the copper interconnects, as the chelating agents mediate the interaction between the cleaning solution and metal surfaces.
Solution Approach 2:
The pH is precisely controlled in the range of 2-4 using buffer agents, which is acidic enough to remove residues effectively but not so acidic as to cause excessive corrosion of copper. The hydrogen peroxide concentration is limited to 0.1-5% to provide oxidative cleaning power while preventing oxidative damage to copper interconnects.
3Reliability
If weak cleaning compositions are used to protect substrate features, then reliability is improved, but residue removal effectiveness deteriorates
Solution Approach 1:
The synergistic combination of hydrogen peroxide (for oxidative cleaning), chelating agents (for selective metal ion binding), and buffer agents (for pH stabilization) creates a composite composition that achieves both high reliability through feature protection and high productivity through effective residue removal.
Solution Approach 2:
Optimized parameter ranges enable the composition to achieve both goals: pH 2-4 provides sufficient cleaning power while protecting features, hydrogen peroxide at 0.1-5% delivers oxidative cleaning effectiveness without causing damage, and chelating agents at 0.01-5% ensure complete metal ion removal while preventing corrosion.
4Manufacturing precision
If multiple cleaning steps are used to achieve complete residue removal, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
Multiple cleaning functions (oxidative cleaning, chelation, pH control, surfactant action) are merged into a single multi-component cleaning composition. This unified formulation eliminates the need for multiple sequential cleaning steps, reducing process complexity while maintaining complete residue removal effectiveness.
Solution Approach 2:
The cleaning composition is designed as a universal multi-functional solution that can remove various types of residues (organic, inorganic, metal-containing) in a single step. The presence of hydrogen peroxide, chelating agents, buffers, and surfactants provides broad-spectrum cleaning capability, replacing multiple specialized cleaning steps.
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 composition effectively removes residues while maintaining the integrity and performance of copper-based interconnects and dielectric materials, enhancing the reliability of integrated circuits by preventing corrosion and residue-related defects.
Implementation Method 1
a chelating agent selected from multifunctional alcohol poly(oxypropylene)polyamine
Implementation Method 2
residues from surfaces of microelectronic device substrates
Data Source
AI summary
The invention provides a composition comprising water, a chelating agent, and a pH adjustor. The invention also provides a method for removing residue from a surface of a microelectronic device substrate comprising contacting the surface of the microelectronic device substrate with a composition comprising water, a chelating agent, and a pH adjustor.