Cleaning Liquid Composition for Semiconductor Substrates
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Solution Overview
Problem
Current cleaning liquids for semiconductor substrates fail to effectively remove metal impurities, fine particles, and organic residues without corroding copper (Cu) surfaces or damaging less noble barrier metals like cobalt (Co), which are essential for advanced semiconductor manufacturing.
Innovation Solution
A cleaning liquid composition comprising basic compounds and nitrogen-containing heterocyclic monocyclic aromatic compounds with carboxyl or ester groups, specifically designed to maintain a pH of 8 to 12, which enhances the removal of metal impurities and organic residues while preventing corrosion of Cu and damage to Co barrier metals by forming protective oxide layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning liquids are used to remove organic residues, then cleaning efficiency is improved, but corrosion of Cu and damage to Co barrier metals occurs
Solution Approach 1:
The patent changes the chemical parameters of the cleaning liquid by specifying precise pH ranges (8.5-10.5 for first cleaning liquid, 10.5-12.0 for second cleaning liquid) and controlled concentrations of basic compounds and chelating agents. These parameter adjustments enable effective removal of organic residues while preventing corrosion of Cu and damage to Co barrier metals through optimized chemical reactivity conditions
Solution Approach 2:
The patent employs composite cleaning liquid formulations combining multiple components: basic compounds (such as ammonia, amine compounds), chelating agents (such as EDTA, NTA), and oxidizing agents (such as hydrogen peroxide). This composite approach creates synergistic effects that enhance cleaning efficiency while the chelating agents specifically protect metal surfaces by forming protective complexes, thus preventing corrosion and damage
2Object-affected harmful factors
If strongly adsorbed anticorrosive agents are used, then corrosion protection is improved, but organic residue removability is lowered
Solution Approach 1:
The patent introduces chelating agents as intermediary substances that mediate between the basic cleaning liquid and metal surfaces. These chelating agents form soluble complexes with metal ions, preventing direct corrosive interactions while allowing the basic compounds to effectively remove organic residues. This intermediary mechanism resolves the conflict between corrosion protection and cleaning efficiency
Solution Approach 2:
The patent optimizes the concentration parameters of both basic compounds and chelating agents to achieve the right balance. By controlling the ratio and concentrations (e.g., basic compound concentration of 0.01-10 wt%, chelating agent concentration of 0.001-1 wt%), the cleaning liquid provides sufficient corrosion protection without interfering with organic residue removal capability
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 cleaning liquid composition effectively removes impurities and organic residues from Cu surfaces without corroding Cu or damaging Co barrier metals, ensuring high cleaning efficiency and substrate integrity, even in the presence of Co as a barrier metal layer.
Implementation Method 1
The cleaning liquid composition comprises one or more basic compounds and one or more nitrogen-containing heterocyclic monocyclic aromatic compounds having one or more carboxyl groups or ester groups
Implementation Method 2
effectively removes impurities and organic residues from Cu surfaces
Implementation Method 3
preventing corrosion of Cu and damage to Co barrier metals by forming protective oxide layers
Data Source
AI summary
Provided is a cleaning liquid composition which is useful for cleaning of a substrate or the like that has been subjected to a chemical mechanical polishing (CMP) process, etc in the production steps of an electronic device such as a semiconductor element. A cleaning liquid composition according to the present invention is used for the purpose of cleaning a substrate that has a Cu wiring, and comprises one or more basic compounds and one or more nitrogen-containing monocyclic heterocyclic aromatic compounds that contain one or more carboxyl groups or ester groups, provided that in cases where one or more amino groups are contained therein, only amino groups directly bonded to a nitrogen-containing heterocyclic rind are contained. This cleaning liquid composition has a hydrogen ion concentration (pH) of 8-12.