Cleaning composition, method for cleaning semiconductor substrate, and method for producing semiconductor element
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Solution Overview
Problem
Existing cleaning compositions for semiconductor substrates struggle to effectively remove residues while preventing copper corrosion, particularly after chemical mechanical polishing (CMP) treatments.
Innovation Solution
A cleaning composition comprising citric acid, 1-hydroxyethane-1,1-diphosphonic acid (HEDPO), and a sulfonic acid-based surfactant, with specific mass ratios and pH control, enhances residue removal and copper anticorrosion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a cleaning liquid containing organic polymer particles and surfactant is used to remove residues, then residue removability is improved, but copper corrosion occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the cleaning liquid by incorporating specific concentrations of citric acid (0.01-10 wt%), HEDPO (0.001-1 wt%), and sulfonic acid-based surfactant (0.001-1 wt%), while controlling pH to 0.10-4.00. This parameter optimization enables effective residue removal while suppressing copper corrosion through balanced chemical formulation.
Solution Approach 2:
The patent creates a composite cleaning liquid formulation that combines multiple functional components: citric acid for chelation and residue removal, HEDPO for copper surface protection and corrosion inhibition, and sulfonic acid-based surfactant for enhancing cleaning efficiency. This composite approach allows simultaneous achievement of residue removability and copper anticorrosion properties.
2Manufacturing precision
If an acidic cleaning composition with polyamino-polycarboxylic acid and surfactant is used, then residue removal capability is enhanced, but copper corrosion resistance deteriorates
Solution Approach 1:
The patent optimizes the acid component by selecting citric acid over polyamino-polycarboxylic acid, and carefully controls the pH range to 0.10-4.00. This parameter change maintains effective residue removal capability while significantly improving copper corrosion resistance compared to conventional acidic compositions.
Solution Approach 2:
The patent introduces HEDPO as an intermediary substance that mediates between the acidic cleaning components and copper surface. HEDPO acts as a corrosion inhibitor that protects copper while allowing the acidic environment to effectively remove residues, thus resolving the contradiction between cleaning effectiveness and copper protection.
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 excellent residue removability and copper anticorrosion performance, as demonstrated by reduced defect counts and lower copper corrosion rates.
Implementation Method 1
The cleaning composition contains citric acid and 1-hydroxyethane-1,1-diphosphonic acid (HEDPO), which are known to form stable complexes with copper ions, preventing copper corrosion while maintaining cleaning effectiveness
Implementation Method 2
The cleaning composition comprises a sulfonic acid-based surfactant, which lowers surface tension and improves wetting properties, enabling effective removal of residues from semiconductor substrates
Implementation Method 3
The cleaning composition effectively removes residues through solvation by water and chemical reactions with citric acid and HEDPO, which dissolve various contaminants on semiconductor substrates
Data Source
AI summary
An object of the present invention is to provide a cleaning composition which has excellent removability of a residue (particularly, a residue after CMP) and excellent anticorrosion properties of copper; a cleaning method of a semiconductor substrate; and a manufacturing method of a semiconductor element. The cleaning composition of the present invention contains citric acid, 1-hydroxyethane-1,1-diphosphonic acid, a sulfonic acid-based surfactant, and water, in which a mass ratio of a content of the citric acid to a content of the 1-hydroxyethane-1,1-diphosphonic acid is 20 to 150, a mass ratio of the content of the citric acid to a content of the sulfonic acid-based surfactant is 70 to 1,500, and a pH is 0.10 to 4.00.