Wafer Edge Rinse Composition for EPL and Hardmask Residue Removal
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Solution Overview
Problem
Current processes for lithographic patterning are inefficient in removing both the edge protection layer (EPL) and residual hardmask components from wafer surfaces, requiring additional costly and time-consuming steps, leading to metal contamination and process delays.
Innovation Solution
A rinse composition comprising between 15% to 35% acetic acid and 65% to 85% anisole, or between 1% to 10% halogenated acetic acid and 90% to 99% anisole, effectively removes EPL and residual hardmask components like tin or titanium from wafer surfaces during lithographic processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate EPL removing solution is used to remove the edge protection layer, then the EPL can be removed effectively, but additional processing steps and time are required
Solution Approach 1:
The patent combines the EPL removal function and hardmask residual component removal function into a single rinse solution. The rinse solution contains both EPL-removing agents (such as oxygen-containing solvents, ketones, or esters) and hardmask-removing agents (such as fluorinated solvents or specific organic compounds), allowing both cleaning tasks to be performed simultaneously in one step rather than requiring separate processing steps.
Solution Approach 2:
The rinse solution is designed with multi-functionality to perform multiple cleaning tasks. It can remove both the organic EPL material and inorganic hardmask residual components (such as metal oxides) through a single application, making the cleaning process universal for different types of contaminants without requiring specialized separate solutions for each contaminant type.
2Object-affected harmful factors
If additional rinsing steps are added to remove residual hardmask components, then metal contamination is reduced, but process complexity and cost increase
Solution Approach 1:
The patent merges the EPL removal step and hardmask residual removal step into a single integrated rinse operation. The rinse solution contains chemically active components that can simultaneously dissolve or detach both organic EPL materials and inorganic hardmask residues, eliminating the need for sequential processing steps and reducing overall process complexity.
Solution Approach 2:
The rinse solution employs a composite chemical formulation combining multiple types of solvents and cleaning agents. This composite rinse solution leverages the synergistic effects of different chemical components to address multiple contaminant types (organic and inorganic) with a single material, rather than requiring separate specialized materials for each contaminant type.
3Quantity of substance
If conventional EBR rinse is used, then some hardmask composition is removed, but residual hardmask components remain on the wafer surface
Solution Approach 1:
The rinse solution uses a composite chemical system that combines EPL-removing agents with hardmask-removing agents. This composite formulation ensures complete removal of hardmask residual components by providing chemical species that can interact with and dissolve metal oxides and other inorganic residues, achieving superior cleaning completeness compared to conventional single-function rinses.
Solution Approach 2:
The patent modifies the chemical parameters of the rinse solution by incorporating specific solvents and chemicals with proven effectiveness against hardmask materials. The rinse solution's chemical composition, pH, and solvent types are optimized to enhance the removal efficiency of hardmask residual components, ensuring thorough cleaning without leaving contaminants on the wafer surface.
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 rinse solution simultaneously and efficiently removes EPL and residual hardmask components, reducing metal contamination and process time, while maintaining commercially acceptable processing times without damaging the hardmask.
Implementation Method 1
a rinse for removing an edge protection layer and residual hardmask components... the rinse includes (i) between approximately 15% by weight and approximately 35% by weight of acetic acid and (ii) between approximately 85% by weight and approximately 65% by weight of a compound having structure B
Implementation Method 2
the rinse includes (i) between approximately 1% by weight and approximately 10% by weight of halogenated acetic acid of structure A... and (ii) between approximately 99% by weight and approximately 90% by weight of a compound having structure B
Data Source
Figure 1~2f
Figure 3~4
AI summary
The disclosed subject matter relates to a rinse and methods of use thereof for removing an edge protection layer and residual hardmask components (e.g., metals) from the edge and at least one proximate surface of a wafer/substrate where the rinse includes acetic acid and/or a halogenated acetic acid of structure (A) wherein R1 and R2 are independently hydrogen or a halogen and R3 is a halogen and (ii) a compound having structure (B) wherein each of Ra, Rb, Rc, Rd, Re, Rf, Rg and Rh may independently be hydrogen, a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted halogenated alkyl group, a substituted or an unsubstituted alkyl carbonyl group, a halogen, and a hydroxy group.