Substrate Treating Method for Particle Suppression
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Solution Overview
Problem
The generation of minute particles during the photo lithography process, which were previously overlooked due to low wettability and high viscosity of chemicals compared to solvents, leads to pattern defects and quality inspection challenges, making it difficult to suppress particle generation effectively.
Innovation Solution
A substrate treating method where a solvent is supplied to the center of the substrate while increasing its rotation speed, forming a solvent pool that expands to cover the entire surface, ensuring smooth and effective coverage and reducing particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the rotation speed of the substrate is rapidly increased after supplying solvent, then the solvent spreads quickly over the substrate surface, but minute particles are generated leading to pattern defects
Solution Approach 1:
The substrate rotation is divided into multiple stages with different rotation speeds. First, the substrate rotates at a first rotation speed to spread the solvent uniformly. Then, it transitions to a second rotation speed for subsequent processing. This periodic change in rotation speed prevents particle generation while ensuring complete solvent coverage.
2Ease of operation
If the solvent is supplied to the substrate at rest, then the solvent can be supplied uniformly, but the solvent does not spread effectively over the substrate surface
Solution Approach 1:
The substrate is rotated at a first rotation speed before and during the solvent supply process. This preliminary rotation creates centrifugal force that facilitates uniform solvent spreading across the substrate surface, combining the benefits of uniform supply and effective coverage.
3Stability of the object's composition
If chemicals with high viscosity and low wettability are used, then the chemical properties are maintained, but particle generation increases and quality inspection becomes difficult
Solution Approach 1:
The rotation speed parameter is changed in two stages: first at a lower speed for uniform chemical supply and then at a higher speed for complete spreading. This parameter optimization ensures that chemicals with high viscosity and low wettability are supplied uniformly while preventing particle generation, maintaining chemical stability without harmful effects.
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 suppresses particle formation by ensuring uniform solvent coverage across the substrate surface, improving process quality and reducing defects in resist film formation.
Implementation Method 1
a rotation speed of the substrate increases slowly... the edge of the core of the solvent A contacts the substrate... the solvent A reaches the periphery edge E of the substrate
Data Source
AI summary
Disclosed is a substrate treating method including a solvent supplying step of supplying a solvent to a center part of a substrate while increasing a rotation speed of the substrate. In the solvent supplying step, the solvent is successively supplied to the substrate until the solvent reaches a periphery edge of the substrate. With such a substrate treating method, the solvent is able to cover a substrate surface entirely with effective suppression of particles. In other words, a process of supplying the solvent to the substrate is performable with effectively improved quality.