Semiconductor Cleaning Solution for Post Etch Residue Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cleaning solutions for semiconductor substrates fail to completely remove post etch residues, including organic and organometallic materials, without damaging wafer features or leaving behind residues, and are not stable during heating and cooling cycles.
Innovation Solution
A cleaning solution comprising a polar aprotic solvent, an inorganic base, a co-solvent, an unsaturated cycloaliphatic compound, an organic amine compound, and a nonionic surfactant, which effectively removes photoresist and post etch residues from semiconductor substrates without etching metal surfaces and remains stable throughout temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning solutions (aromatic quaternary ammonium hydroxide, pyrrolidone-based solvents) are used to remove photoresist, then some resist removal is achieved, but complete removal of dry-film resists is not achieved and compatibility problems with photoresists and cured polyimide layers occur
Solution Approach 1:
The invention uses a composite cleaning solution containing N-methyl-2-pyrrolidone (NMP) as the primary solvent, combined with specific additives including aromatic quaternary ammonium hydroxide, cyclic carboxylic acid, and surfactants. This composite formulation achieves complete dry-film resist removal while maintaining compatibility with cured polyimide layers and photoresists, resolving the contradiction between removal effectiveness and material compatibility.
Solution Approach 2:
The invention optimizes the concentration parameters of each component in the cleaning solution, specifically using NMP at 70-95 wt%, aromatic quaternary ammonium hydroxide at 0.1-5 wt%, cyclic carboxylic acid at 0.1-5 wt%, and surfactants at 0.1-5 wt%. These parameter adjustments enable complete resist removal without damaging underlying layers, solving the contradiction between removal completeness and layer compatibility.
2Productivity
If high energy plasma process is used to remove Cu film and organic dielectric film, then film removal is achieved, but photoresist residues and plasma decomposition products remain as post etch residues
Solution Approach 1:
The invention converts the harmful plasma decomposition products and photoresist residues into removable substances by using a cleaning solution specifically designed to dissolve these materials. The NMP-based solution with cyclic carboxylic acid and surfactants effectively dissolves the organometallic and organic residues generated during plasma etching, transforming the harmful residues into soluble compounds that can be completely removed from the wafer surface.
Solution Approach 2:
The cleaning solution acts as an intermediary between the plasma etching process and the final clean wafer surface. It mediates the removal of harmful residues by providing a chemical environment that dissolves and suspends plasma decomposition products, organometallic compounds, and photoresist residues, enabling their complete removal without direct mechanical intervention.
3Productivity
If vaporized metal and organometallic compounds are removed during plasma etching, then film deposition is achieved, but these materials sublime or sputter onto and deposit onto other features on the wafer surface
Solution Approach 1:
The invention addresses the harmful vapor deposition by using a cleaning solution that specifically targets and dissolves the deposited organometallic and metal oxide materials. The cyclic carboxylic acid and surfactant components chelate with metal ions and emulsify organic deposits, converting the harmful deposited materials into soluble complexes that can be completely removed from solder bumps and other wafer features.
4Manufacturing precision
If cleaning solution is heated and cooled during operation, then cleaning effectiveness is improved, but solution stability deteriorates and precipitates may form
Solution Approach 1:
The invention optimizes the chemical composition parameters to ensure stability during temperature cycling. The specific combination of NMP, aromatic quaternary ammonium hydroxide, cyclic carboxylic acid, and nonionic surfactants creates a solution that remains homogeneous and stable when heated to cleaning temperatures and then cooled, preventing precipitation while maintaining cleaning effectiveness throughout the temperature cycle.
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 solution effectively cleans post etch residues from semiconductor substrates, including those on solder bump walls and top surfaces, while maintaining compatibility with metal features and remaining stable during heating and cooling, ensuring no residue deposition on the wafer or equipment.
Implementation Method 1
A cleaning solution comprising a polar aprotic solvent, an inorganic base, a co-solvent, an unsaturated cycloaliphatic compound, an organic amine compound, and a nonionic surfactant, which effectively removes photoresist and post etch residues from semiconductor substrates
Implementation Method 2
an inorganic base
Implementation Method 3
an inorganic base
Implementation Method 4
a nonionic surfactant
Implementation Method 5
remains stable throughout temperature changes
Data Source
AI summary
A photoresist and post etch cleaning solution for semiconductor wafers comprising:A. a polar aprotic solvent,B. an inorganic base;C. a co-solvent for said inorganic base;D. a unsaturated cycloaliphatic compound having a ring ether group and at least one substituent bearing a primary hydroxyl group;E. an organic base comprising an amine compound; andF. a nonionic surfactant bearing at least one ether group.The wafer containing photoresist residue or post etch residue can be cleaned by contacting the solution in a spray or immersion.