Cleaning Liquid for Metal Resist Substrates
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Solution Overview
Problem
Current cleaning liquids containing organic solvents and carboxylic acids are inadequate for effectively removing metal residues from substrates after patterning with metal resist, particularly in semiconductor processing.
Innovation Solution
A cleaning liquid comprising a solvent, an organic acid, and a chelating compound represented by general formula (a-1), which includes a solvent such as propylene glycol methyl ethyl acetate, formic acid, and a chelating agent, is used to improve metal removability from substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cleaning liquid containing an organic solvent and a carboxylic acid is used, then cleaning capability is provided, but metal removability is insufficient
Solution Approach 1:
The cleaning liquid uses a composite composition containing a cyclic carboxylic acid (such as citric acid or oxalic acid) combined with specific organic solvents. This composite approach leverages the chelating ability of cyclic carboxylic acids to form stable complexes with metal ions, significantly improving metal removability while maintaining cleaning effectiveness on organic residues.
Solution Approach 2:
The invention changes the chemical parameters of the cleaning liquid by specifying particular cyclic carboxylic acids with defined molecular structures (formula 1 where R1-R6 are specific groups). This parameter optimization ensures the cleaning liquid has sufficient chelating power for metal removal while controlling aggressiveness toward the substrate and resist patterns.
2Reliability
If strong cleaning agents are used to remove metal residues, then metal removability improves, but damage to substrate or resist patterns increases
Solution Approach 1:
The invention optimizes the chemical parameters by using cyclic carboxylic acids with specific structural characteristics (formula 1) that provide sufficient chelating strength for metal removal while being gentle enough not to damage the substrate or resist patterns. The molecular structure parameters (R1-R6 groups) are carefully selected to balance cleaning power and selectivity.
Solution Approach 2:
The cyclic carboxylic acid acts as an intermediary chelating agent that selectively binds to metal ions through its carboxyl groups, forming soluble complexes that can be easily rinsed away. This intermediary mechanism allows metal removal without requiring strong acids or bases that could damage the substrate.
3Reliability
If conventional cleaning liquids are used, then processing simplicity is maintained, but residue removal effectiveness is insufficient
Solution Approach 1:
The cleaning liquid employs a composite formulation combining cyclic carboxylic acids with specific organic solvents in defined ratios. This composite approach achieves superior residue removal effectiveness while maintaining relatively simple preparation procedures, as the components are mixed in specific proportions to create a synergistic cleaning solution.
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 demonstrates enhanced metal removability, as evidenced by reduced residual metal on the substrate, particularly when used in edge rinsing processes, improving the reliability of semiconductor manufacturing.
Implementation Method 1
a compound (A) which satisfies general formula (a-1) shown below... exhibits improved metal removability
Implementation Method 2
the cleaning liquid including a solvent, an organic acid, and a compound (A)... improved metal removability
Implementation Method 3
a cleaning liquid containing an organic solvent and a carboxylic acid... metal removability
Implementation Method 4
the cleaning liquid including a solvent, an organic acid... cleaning a substrate provided with a metal resist
Data Source
AI summary
A cleaning liquid usable for cleaning a substrate provided with a metal resist, the cleaning liquid including a solvent, an organic acid, and a compound (A) represented by general formula (a-1) shown below (in the formula, Ra1 and Ra2 each independently represents an alkyl group having 1 to 3 carbon atoms).