Siloxane-Alkane Rinse Composition for Sub-50 Nm Pattern Collapse
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Solution Overview
Problem
Existing compositions for manufacturing integrated circuits with sub-50 nm features suffer from pattern collapse during chemical rinse and spin dry processes due to capillary forces, particularly after alkaline pretreatments like SC1, affecting structures with high aspect ratios.
Innovation Solution
A non-aqueous composition comprising a non-polar organic solvent, such as linear or branched C5 to C12 alkane, combined with a siloxane-type non-ionic additive, effectively prevents pattern collapse by minimizing surface tension and capillary forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional aqueous rinse solutions are used for cleaning patterned structures, then particle removal is effective, but capillary forces cause pattern collapse in sub-50 nm structures
Solution Approach 1:
The patent changes the physical-chemical parameters of the rinse solution by using non-aqueous solvents (isopropyl alcohol, ethyl carbonate, dimethyl sulfoxide) instead of conventional aqueous solutions. This parameter change reduces the surface tension and capillary forces acting on sub-50 nm patterns, preventing pattern collapse while maintaining effective particle removal capability.
Solution Approach 2:
The patent employs composite formulations combining multiple non-aqueous solvents (e.g., isopropyl alcohol with ethyl carbonate, or dimethyl sulfoxide with hydrocarbons like hexane) to achieve optimal balance between particle removal efficiency and capillary force reduction. This composite approach allows tuning of solvent properties to simultaneously address both cleaning effectiveness and pattern integrity.
2Manufacturing precision
If alkaline pretreatment (SC1) is applied to remove particles and residues, then cleaning effectiveness improves, but pattern collapse increases in sub-50 nm structures
Solution Approach 1:
The patent applies alkaline pretreatment (SC1 solution containing ammonia and hydrogen peroxide) as a preliminary cleaning step before the non-aqueous rinse. This preliminary action removes particles and plasma etch residues effectively, and the subsequent non-aqueous rinse then prevents pattern collapse during the main cleaning process, combining the benefits of both approaches.
Solution Approach 2:
The non-aqueous rinse solution acts as an intermediary between the alkaline pretreatment and the final drying step. It provides a transition medium that maintains pattern stability while allowing effective removal of residues, bridging the gap between aggressive cleaning and gentle handling requirements.
3Productivity
If spin dry process is used to remove liquid, then drying efficiency improves, but capillary forces increase causing pattern collapse
Solution Approach 1:
The patent changes the liquid properties by using non-aqueous solvents with lower surface tension compared to water. This parameter change reduces the capillary forces generated during spin drying, allowing efficient liquid removal while minimizing the harmful capillary forces that cause pattern collapse in high aspect ratio structures.
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 significantly reduces pattern collapse in structures with line-space dimensions of 50 nm or less and aspect ratios greater than 4, maintaining substrate integrity during processing.
Implementation Method 1
a non-aqueous composition comprising a non-polar organic solvent, such as linear or branched C5 to C12 alkane, combined with a siloxane-type non-ionic additive, effectively prevents pattern collapse by minimizing surface tension and capillary forces
Implementation Method 2
These structures may suffer from bending and/or collapsing, in particular, during the spin dry process, due to excessive capillary forces of the liquid or solution of the rinsing liquid deionized water remaining from the chemical rinse and spin dry processes
Data Source
AI summary
Described herein is a non-aqueous composition including(a) an organic solvent;and(b) at least one additive of formulae I or IIwhereR1 is HR2 is selected from the group consisting of H, C1 to C10 alkyl, C1 to C10 alkoxy, C6 to C10 aryl, and C6 to C10 aroxy,R3 is selected from the group consisting of R2,R4 is selected from the group consisting of C1 to C10 alkyl, C1 to C10 alkoxy, C6 to C10 aryl, and C6 to C10 aroxy,R10, R12 are independently selected from the group consisting of C1 to C10 alkyl and C1 to C10 alkoxy,m is 1, 2 or 3, andn is 0 or an integer from 1 to 100.