Wafer Edge Bead Rinse for Metal Residue Removal
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Solution Overview
Problem
Existing edge bead removal solutions for metal-containing resists are inadequate in effectively reducing metal residue along the wafer edges, particularly for semiconductor processing, where traditional organic photoresist solvents fail to achieve desired levels of contamination reduction.
Innovation Solution
A method involving the application of a bead edge rinse solution comprising organic solvents and additives such as carboxylic acids, inorganic fluorinated acids, or tetraalkylammonium compounds, along with the use of sacrificial layers and anti-adhesion coatings to facilitate the removal of metal-based resist materials from the wafer edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional organic photoresist solvents are used for edge bead removal, then the process is simple and compatible with existing equipment, but metal residue contamination remains high and ineffective reduction is achieved
Solution Approach 1:
The patent modifies the chemical composition parameters of the rinse solution by incorporating specific additives (carboxylic acids, inorganic fluorinated acids, or tetraalkylammonium compounds) alongside organic solvents. This parameter change enables effective metal residue removal while maintaining process compatibility with existing semiconductor manufacturing equipment.
Solution Approach 2:
The invention uses composite rinse solutions combining multiple components: organic solvents (for resist removal) and specialized additives (for metal residue reduction). This composite approach achieves both functions simultaneously, resolving the contradiction between effective contamination removal and process simplicity.
2Manufacturing precision
If metal-based resists are used to achieve good absorption and high etch contrast, then patterning performance is improved, but metal residue contamination on wafer edges increases
Solution Approach 1:
The patent selectively targets and extracts metal residues from the edge bead region using specialized rinse solutions. The additives in the solution specifically bind to and remove metal contaminants while leaving the patterned resist intact, thus separating the beneficial patterning function from the harmful residue contamination.
Solution Approach 2:
The rinse solution acts as an intermediary substance that mediates between the metal-based resist (which provides good patterning) and the wafer surface (which should remain clean). The carboxylic acids, fluorinated acids, or tetraalkylammonium compounds in the solution facilitate metal residue removal without affecting the patterning quality.
3Object-affected harmful factors
If edge bead rinse is performed to remove resist material, then edge cleanliness is improved, but metal residue remains if traditional solvents are used
Solution Approach 1:
The patent changes the chemical parameters of the rinse solution by adding specific additives that enhance metal residue removal capability. This parameter modification enables the rinse process to simultaneously remove both resist material and metal contaminants, achieving the desired reduction in metal contamination levels.
Solution Approach 2:
The invention employs composite rinse solutions that combine organic solvents (for resist removal) with specialized additives (for metal residue reduction). This composite formulation achieves dual functionality, removing both types of contamination effectively and reducing metal contamination to acceptable levels.
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
Significantly reduces residual metal contamination, achieving low levels of tin and other metals on the wafer edges, thereby enhancing the commercialization of metal-based resists in semiconductor processing and ensuring cleaner processing equipment.
Implementation Method 1
applying a first bead edge rinse solution along a wafer edge following spin coating of the wafer with the resist composition
Implementation Method 2
the edge bead solution comprises an organic solvent and an additive comprising a carboxylic acid, an inorganic fluorinated acid, a tetraalkylammonium compound, or a mixture thereof
Data Source
AI summary
Apparatuses and methods are described for removing edge bead on a wafer associated with a resist coating comprising a metal containing resist compositions. The methods can comprise applying a first bead edge rinse solution along a wafer edge following spin coating of the wafer with the metal based resist composition, wherein the edge bead solution comprises an organic solvent and an additive comprising a carboxylic acid, an inorganic fluorinated acid, a tetraalkylammonium compound, or a mixture thereof. Alternatively or additionally, the methods can comprise applying a protective composition to the wafer prior to performing an edge bead rinse. The protective composition can be a sacrificial material or an anti-adhesion material and can be applied only to the wafer edge or across the entire wafer in the case of the protective composition. Corresponding apparatuses for processing the wafers using these methods are presented.