Substrate Drying with Solvent Gas Film for Pattern Collapse Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor device production, the spin drying method often causes collapse of minute patterns with higher aspect ratios due to surface tension issues, as water entering pattern gaps is not properly spun off, and organic solvents alone may not sufficiently prevent pattern collapse during cleaning.
Innovation Solution
A substrate treatment method involving a rinsing step with deionized water, followed by an organic solvent with lower surface tension to replace water in pattern gaps, and a higher temperature maintenance step to form a gas film, reducing surface tension and preventing pattern collapse, along with an organic solvent removal step to efficiently dry the substrate without friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spin drying method is used to remove liquid from substrate, then drying efficiency is improved, but pattern collapse occurs due to surface tension
Solution Approach 1:
The patent changes the physical parameter of the liquid by using organic solvent instead of water, which has lower surface tension. This parameter change allows the liquid to be removed without causing pattern collapse while maintaining drying efficiency
Solution Approach 2:
The organic solvent acts as an intermediary substance that replaces water in the pattern gaps. It mediates between the need for efficient drying and the need to prevent pattern collapse by providing a liquid with appropriate surface tension properties
2Manufacturing precision
If organic solvent is supplied to replace water in pattern gaps, then pattern collapse is prevented, but drying completeness deteriorates
Solution Approach 1:
The patent utilizes phase transition by heating the substrate to evaporate the organic solvent. The temperature is raised above the boiling point of the organic solvent to transform it from liquid to gas phase, ensuring complete removal while maintaining pattern integrity during the liquid phase
3Productivity
If substrate temperature is raised above boiling point of organic solvent, then solvent removal is improved, but pattern collapse risk increases during heating
Solution Approach 1:
The organic solvent is supplied to the substrate before heating is initiated. This preliminary action ensures that the solvent is already in place to prevent pattern collapse during the subsequent heating and drying process
Solution Approach 2:
The organic solvent continuously covers the pattern surfaces throughout the heating process, maintaining pattern integrity from the liquid phase through the phase transition to complete evaporation, ensuring uninterrupted protection
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
This method effectively prevents pattern collapse during cleaning of substrates with high aspect ratio patterns by reducing surface tension and ensuring proper removal of liquids, allowing for reliable drying of substrates while maintaining pattern integrity.
Implementation Method 1
an organic solvent supplying step of supplying an organic solvent having a smaller surface tension than the rinse liquid to the upper surface of the substrate held by the substrate holding unit to form a liquid film of the organic solvent on the upper surface so that rinse liquid adhering to the upper surface of the substrate including a gap of the minute pattern is replaced with the organic solvent
Implementation Method 2
a higher temperature maintaining step of maintaining the upper surface of the substrate held by the substrate holding unit at a predetermined temperature higher than the boiling point of the organic solvent to thereby form a gas film of the organic solvent on the entire upper surface of the substrate including the gap of the minute pattern
Data Source
AI summary
The inventive substrate treatment method includes: an organic solvent supplying step of supplying an organic solvent having a smaller surface tension than a rinse liquid to the upper surface of a substrate so that rinse liquid adhering to the upper surface of the substrate is replaced with the organic solvent; a higher temperature maintaining step of maintaining the upper surface of the substrate at a predetermined temperature higher than the boiling point of the organic solvent to thereby form a gas film of the organic solvent on the entire upper surface of the substrate including the gap of the minute pattern and to form a liquid film of the organic solvent on the gas film, the higher temperature maintaining step being performed after the organic solvent supplying step is started; and an organic solvent removing step of removing the organic solvent liquid film from the upper surface of the substrate.