Semiconductor Cleaning Liquid for Low-k Film Protection
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Solution Overview
Problem
Current cleaning methods for semiconductor manufacturing fail to effectively remove dry etch residues while minimizing damage to low-dielectric-constant films, cobalt, tungsten plugs, hardmasks, barrier metals, and barrier insulating films, leading to compromised electrical characteristics and structural integrity.
Innovation Solution
A cleaning liquid comprising 0.001-20% alkali metal compounds, 0.1-30% quaternary ammonium hydroxides, 0.01-60% organic water-soluble solvents, and 0.0001-0.1% hydrogen peroxide is used to selectively remove dry etch residues, preventing damage to these sensitive materials during the semiconductor manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxygen plasma is used to remove dry etch residues, then removal effectiveness is improved, but damage to Low-k film increases significantly
Solution Approach 1:
The patent changes the cleaning method from oxygen plasma to a liquid cleaning composition with specific chemical parameters (containing quaternary ammonium hydroxide, organic solvent, and water in specific ratios). This parameter change allows effective removal of dry etch residues while avoiding the damaging effects of oxygen plasma on Low-k films.
Solution Approach 2:
The patent introduces a liquid cleaning composition as an intermediary substance that mediates between the need for effective residue removal and the need to protect sensitive films. The composition contains quaternary ammonium hydroxide and organic solvents that act as intermediate agents to dissolve and remove residues without directly damaging the Low-k film structure.
2Manufacturing precision
If conventional cleaning liquids are used to remove dry etch residues, then some residues are removed, but removal completeness is insufficient
Solution Approach 1:
The patent uses a composite cleaning liquid composition containing multiple components (quaternary ammonium hydroxide, organic solvent, and water) that work synergistically. The quaternary ammonium hydroxide provides strong cleaning power, the organic solvent enhances residue dissolution, and water acts as a carrier and rinsing agent, together achieving complete residue removal.
Solution Approach 2:
The patent optimizes the concentration ratios of each component in the cleaning liquid to achieve maximum cleaning effectiveness. By adjusting these parameters, the composition achieves complete removal of dry etch residues while maintaining compatibility with sensitive semiconductor structures.
3Productivity
If cleaning methods are optimized for residue removal, then cleaning effectiveness is improved, but damage to cobalt, tungsten, hardmask, and barrier films increases
Solution Approach 1:
The patent creates a cleaning composition with locally optimized properties where different components target different types of residues and protect different sensitive materials. The quaternary ammonium hydroxide targets organic residues, the organic solvent addresses inorganic residues, and the overall composition is formulated to be gentle on cobalt, tungsten, hardmask, and barrier films while maintaining high cleaning efficiency.
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 proposed cleaning method achieves complete removal of dry etch residues while maintaining the integrity of low-k films, cobalt, tungsten plugs, hardmasks, and barrier metals, ensuring high-quality semiconductor element production with improved yield and reduced damage.
Implementation Method 1
a cleaning liquid containing 0.001-20% by mass of an alkali metal compound, 0.1-30% by mass of a quaternary ammonium hydroxide
Implementation Method 2
0.0001-0.1% by mass of hydrogen peroxide
Implementation Method 3
0.01-60% by mass of an organic water-soluble solvent
Data Source
Figure 1~2
AI summary
The present invention makes it possible to provide a semiconductor element cleaning method that is characterized in that: a hard mask pattern is formed on a substrate that has a low relative permittivity film and at least one of a cobalt, a cobalt alloy, or a tungsten plug; and a cleaning liquid that contains 0.001-20% by mass of an alkali metallic compound, 0.1-30% by mass of quaternary ammonium hydroxide, 0.01-60% by mass of a organic water-soluble solvent, 0.0001-0.1% by mass of hydrogen peroxide, and water is subsequently used on a semiconductor element in which, using the hard mask pattern as a mask, the hard mask, the low relative permittivity film, and a barrier insulating film are dry etched, and dry etch residues are removed.