Post-CMP Cleaning Composition for Low-k Dielectric Protection
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Solution Overview
Problem
Conventional cleaning chemistries for microelectronic devices often damage low-k dielectric materials, absorb into the pores of interlevel dielectric layers, corrode metal structures, and fail to effectively remove post-CMP, post-etch, and post-ash residues, which can lead to poor electrical performance and adhesion issues.
Innovation Solution
A cleaning composition comprising a quaternary base, organic amine, and specific corrosion inhibitors such as 4-methylpyrazole, pyrazole, and 2-amino-thiazole, which is substantially devoid of alkali hydroxides, alkaline earth metal hydroxides, and tetramethylammonium hydroxide, effectively removes residues without damaging low-k dielectric materials or corroding metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning chemistries are used to remove residues, then residue removal effectiveness is improved, but damage to low-k dielectric materials and corrosion of metal structures occurs
Solution Approach 1:
The patent changes the chemical parameters of the cleaning composition by using specific corrosion inhibitors (benzotriazole, pyrazole, imidazole, triazole, or tetramethylammonium hydroxide) at controlled concentrations (0.01-5% weight percent) to achieve effective residue removal while preventing damage to low-k dielectric materials and corrosion of metal structures. This parameter optimization resolves the contradiction between cleaning effectiveness and material safety.
Solution Approach 2:
The corrosion inhibitor acts as an intermediary substance that mediates between the cleaning chemistry and the sensitive microelectronic structures. It protects the low-k dielectric materials and metal interconnects from harmful effects while allowing the cleaning composition to remove residues effectively, thus resolving the contradiction between cleaning power and material protection.
2Productivity
If strong cleaning agents are used to remove post-CMP residues, then cleaning efficiency is improved, but adhesion of post-CMP applied layers deteriorates
Solution Approach 1:
The patent optimizes the pH and chemical composition parameters of the cleaning solution by incorporating corrosion inhibitors at specific concentrations. This creates a balanced cleaning environment that efficiently removes residues while maintaining surface properties necessary for good adhesion of subsequent layers, resolving the contradiction between cleaning efficiency and adhesion quality.
3Reliability
If alkali hydroxides are used in cleaning composition, then residue removal capability is improved, but environmental friendliness and material safety deteriorate
Solution Approach 1:
The patent replaces persistent and environmentally harmful alkali hydroxides with more environmentally benign corrosion inhibitors that are effective at lower concentrations and have shorter environmental persistence. This substitution maintains residue removal capability while reducing environmental impact and material damage risks.
Solution Approach 2:
The patent changes the chemical composition parameters by eliminating alkali hydroxides and using alternative corrosion inhibitors (benzotriazole, pyrazole, imidazole, triazole, or tetramethylammonium hydroxide) at optimized concentrations. This parameter change achieves effective cleaning while improving environmental friendliness and material safety.
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, ensuring reliable electrical performance and adhesion of post-CMP applied layers, while being environmentally friendly and non-damaging to low-k dielectric materials and metal structures.
Implementation Method 1
A cleaning composition comprising a quaternary base, organic amine, and specific corrosion inhibitors effectively removes residues without damaging low-k dielectric materials or corroding metals
Implementation Method 2
The composition comprises at least one quaternary base, at least one organic amine, at least one corrosion inhibitor, and at least one solvent wherein the corrosion inhibitor is selected from the group consisting of 4-methylpyrazole, pyrazole, 2-amino-thiazole, 2-amino-1,3,4-thiadiazole, pterine, pyrazine, cytosine, pyridazine, derivatives thereof, and combinations thereof
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.