Alkaline Cleaning Composition for 3D Semiconductor Residue Removal
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Solution Overview
Problem
Conventional cleaning compositions for 3D semiconductor structures are ineffective in removing post-etch residues without damaging the materials, leading to cross-contamination and reduced electrical performance due to volatility, solubility, and electrochemical potential differences between chalcogenide and metal elements.
Innovation Solution
A composition comprising greater than 99% water, a base such as tetramethylammonium hydroxide, a polydentate chelator like ethylenediamine tetraacetic acid, and a fluorine source like ammonium fluoride, which maintains a pH of 10.0 to 12.0 to solubilize metal ions and reduce the formation of insoluble complexes, thereby minimizing cross-contamination and damage to organic materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional solvent-based or acid-based compositions are used to clean post-etch residues, then residues are removed, but cross-contamination occurs and electrical performance deteriorates
Solution Approach 1:
The invention changes the fundamental chemical parameter of the cleaning composition from acidic/solvent-based to alkaline-based (pH 10-12). This parameter change enables effective residue removal while preventing the galvanic corrosion and metal migration that occur with conventional compositions, thereby maintaining electrical performance.
Solution Approach 2:
The invention uses a composite cleaning composition containing multiple alkaline agents including tetramethylammonium hydroxide, ethylenediamine tetraacetic acid, dipropylene glycol, and ammonium fluoride. This composite formulation provides synergistic effects that enable comprehensive residue removal while protecting sensitive stack structure materials from damage.
2Object-affected harmful factors
If multiple compositions are used to clean different materials, then damage to stack structures is reduced, but process complexity increases
Solution Approach 1:
The alkaline-based cleaning composition is designed to be universally effective against all types of post-etch residues on the stack structure, including chalcogenide materials, metal elements, and organic materials. This single multi-functional composition replaces the need for multiple specialized cleaning steps, thereby reducing process complexity while maintaining protection of sensitive materials.
3Manufacturing precision
If conventional compositions are used, then some residues are removed, but metal elements migrate and form insoluble complexes
Solution Approach 1:
The invention converts the harmful acidic environment that causes metal migration into a beneficial alkaline environment. The alkaline conditions suppress galvanic corrosion and prevent metal element migration, while the chelating agents in the composition actively bind metal ions to prevent insoluble complex formation. This transforms the cleaning process from harmful to beneficial.
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 effectively removes residues from 3D cross-point memory structures without damaging the materials, improving electrical properties and reducing the complexity of the fabrication process, while being cost-effective compared to conventional solvent- or acid-based compositions.
Implementation Method 1
a polydentate chelator like ethylenediamine tetraacetic acid... to solubilize metal ions and reduce the formation of insoluble complexes
Implementation Method 2
Conventional compositions are typically solvent-based or acid-based to decrease galvanic corrosion and other damage of the stack structures
Implementation Method 3
the composition effectively removes residues from 3D cross-point memory structures without damaging the materials
Data Source
AI summary
Compositions for removing residues from a semiconductor structure. The compositions comprise water, a base, a polydentate chelator, a degasser, and a fluorine source. The compositions comprise greater than or equal to approximately 99 wt % of the water and are formulated to exhibit a pH of from approximately 10.0 to approximately 12.0. Methods of forming and using the compositions are also disclosed.