Post-CMP Cleaning Composition for Cobalt and Low-k Dielectrics
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Solution Overview
Problem
Conventional cleaning compositions for microelectronic devices often damage low-k dielectric materials, corrode metal interconnects, and fail to effectively remove post-CMP, post-etch, and post-ash residues, particularly those containing cobalt, leading to poor electrical performance and adhesion issues.
Innovation Solution
A cleaning composition devoid of alkali hydroxides, alkaline earth metal hydroxides, and tetramethylammonium hydroxide, comprising organic amines, quaternary bases, complexing agents, reducing agents, and optional etchants and additives, which effectively removes residues without damaging cobalt-containing materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning compositions are used to remove residues, then residue removal effectiveness is improved, but damage to cobalt-containing materials and low-k dielectric materials occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the cleaning solution by replacing conventional alkali hydroxides and tetramethylammonium hydroxide with alternative cleaning agents that have different chemical properties. This parameter change allows the solution to effectively remove residues while being compatible with cobalt-containing materials and low-k dielectric materials, thus resolving the contradiction between cleaning effectiveness and material damage.
Solution Approach 2:
The patent introduces intermediary substances that mediate between the cleaning action and the sensitive materials. These intermediary agents enable effective residue removal while protecting cobalt and low-k dielectric materials from damage, acting as a bridge that allows the cleaning process to occur without harmful interactions with the protected materials.
2Reliability
If strong cleaning agents are used to remove post-CMP and post-etch residues, then cleaning effectiveness is improved, but corrosion of metal interconnects occurs
Solution Approach 1:
The patent modifies the chemical parameters of the cleaning solution by eliminating strong alkali components that cause corrosion. The alternative composition maintains cleaning effectiveness through different chemical mechanisms that do not involve aggressive corrosion-prone reactions with metal interconnects.
Solution Approach 2:
The patent converts potentially harmful chemical reactions into beneficial ones by using cleaning agents that remove residues through mechanisms that do not corrode metals. The harmful corrosive action is transformed into a selective cleaning action that targets residues while sparing metal interconnects.
3Reliability
If conventional cleaning chemistries are used for post-etch residue removal, then residue removal is improved, but absorption into ILD pores increases dielectric constant
Solution Approach 1:
The patent changes the chemical composition to use cleaning agents that do not have the property of being absorbed into porous ILD materials. This parameter change in the cleaning solution's chemical nature prevents the absorption issue while maintaining effective residue removal capability.
Solution Approach 2:
The patent uses intermediary cleaning agents that selectively interact with residues on the surface without penetrating into the ILD pores. These intermediary substances act as a bridge between the residue removal function and the ILD protection requirement.
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 achieves at least 99% removal of residues while maintaining compatibility with cobalt and low-k dielectric materials, preventing corrosion and ensuring reliable electrical performance.
Implementation Method 1
The cleaning composition comprises at least one organic amine, at least one solvent, at least one quaternary base, and at least one complexing agent
Implementation Method 2
The cleaning composition comprises at least one reducing agent
Data Source
AI summary
A cleaning composition and process for cleaning post-chemical mechanical polishing (CMP) residue and contaminants from a microelectronic device having said residue and contaminants thereon. The cleaning compositions are substantially devoid of alkali hydroxides, alkaline earth metal hydroxides, and tetramethylammonium hydroxide. The composition achieves highly efficacious cleaning of the post-CMP residue and contaminant material from the surface of the microelectronic device without compromising the low-k dielectric material or the copper interconnect material.