Low Surface Tension Cleaning Solution for Pattern Collapse Prevention
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Solution Overview
Problem
The challenge in semiconductor integrated circuit (IC) fabrication is the collapse of high aspect ratio features during processing due to critical dimension scaling, which leads to manufacturing inefficiencies and increased complexity.
Innovation Solution
A method involving the use of a chemical solution with low surface tension to prevent pattern collapse during the cleaning process, specifically formulated with organic solvents, surfactants, and pH buffering agents to maintain a critical aspect ratio and support feature stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If critical dimension is scaled down to increase functional density, then production efficiency is improved and costs are lowered, but the feature may collapse due to high aspect ratio
Solution Approach 1:
The patent changes the physical-chemical parameters of the cleaning solution by incorporating compounds with low surface tension (such as fluorinated surfactants or organic solvents like propylene glycol monomethyl ether acetate). This parameter change reduces the surface tension of the cleaning solution, thereby reducing capillary forces on the patterns during cleaning and preventing pattern collapse while maintaining cleaning effectiveness
Solution Approach 2:
The patent introduces a low surface tension compound as an intermediary substance in the cleaning solution. This intermediary reduces the harmful capillary forces between the cleaning solution and the high aspect ratio patterns, acting as a mediator that allows effective cleaning without causing pattern collapse
2Manufacturing precision
If high aspect ratio features are formed to maintain functionality at smaller dimensions, then functional density is improved, but pattern collapse occurs during fabrication
Solution Approach 1:
The patent modifies the surface tension parameter of the cleaning solution by adding low surface tension compounds. This parameter change directly addresses the stability issue by reducing capillary forces that cause pattern collapse, allowing high aspect ratio features to maintain their structural integrity during the cleaning process
3Reliability
If conventional cleaning solutions are used on high aspect ratio patterns, then cleaning effectiveness is maintained, but surface tension causes pattern collapse
Solution Approach 1:
The patent converts the harmful high surface tension property of conventional cleaning solutions into a beneficial low surface tension property by adding surfactants or organic solvents. This transformation reduces capillary forces from harmful to beneficial, allowing the cleaning solution to effectively clean patterns without causing collapse
Solution Approach 2:
The patent changes the surface tension parameter of the cleaning solution from high to low by incorporating specific compounds. This parameter change simultaneously maintains cleaning effectiveness while eliminating the harmful capillary forces that cause pattern collapse in high aspect ratio features
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 low surface tension chemical solution effectively prevents pattern collapse, allowing for higher aspect ratios and reducing the risk of feature failure during IC fabrication, thereby enhancing processing efficiency and manufacturing reliability.
Implementation Method 1
A method is disclosed for preventing pattern collapse during a cleaning process by reducing a surface tension of the chemical solution used during the cleaning process
Data Source
AI summary
A chemical solution for use in cleaning a patterned substrate includes water, from approximate 0.01 to 99.98 percent by weight; hydrogen peroxide, from 0 to 30 percent by weight; a pH buffering agent, from approximate 0.01 to 50 percent by weight; a metal chelating agent, from approximate 0 to 10 percent by weight; and a compound for lowering a surface tension of the combination of water, hydrogen peroxide, pH buffering agent, and metal chelating agent. Examples of the compound include an organic solvent, from approximate 0 to 95 percent by weight, or a non-ionic surfactant agent, from approximate 0 to 2 percent by weight.