Substrate Treating Cup Protrusion Vortex Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing substrate treating apparatuses face issues with inefficient air flow evacuation, vortex generation, and contaminant re-adsorption during the photolithography process, leading to non-uniform film thickness and substrate contamination when treating rotating substrates with a liquid.
Innovation Solution
The apparatus features a treating container with an outer and inner cup design, including a protrusion along the side wall of the outer cup and a pressure adjustment member, which creates equal passage widths for airflow to prevent vortex formation and ensure smooth exhaust, along with a liquid supply unit for uniform liquid film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the space between the outer cup and inner cup is made larger to facilitate air flow, then air evacuation is improved, but a vortex is generated near the bottom plate due to the mismatch with the exhaust tube space width
Solution Approach 1:
The patent applies local quality by creating different passage widths at different locations. The first passage (between outer cup and inner cup) has a greater width than the second passage (between inner cup and exhaust tube), which prevents vortex formation by controlling the air flow characteristics at each specific location rather than using a uniform width throughout.
Solution Approach 2:
The patent employs asymmetry by deliberately making the first passage width different from the second passage width. This asymmetric design prevents the air flow from forming a vortex by creating a controlled flow path that transitions smoothly from the larger first passage to the narrower second passage, ultimately discharging air without harmful vortices.
2Ease of operation
If the air flow is allowed to move freely from center to edge, then the substrate treatment process is simplified, but the air flow becomes stagnant and contaminants flow back to contaminate the substrate
Solution Approach 1:
The patent introduces an intermediary exhaust tube system with controlled passage widths that mediates the air flow between the substrate treatment space and the external environment. This intermediary structure guides the air flow from the center to the edge and then to the exhaust tube, preventing direct contact between stagnant air/contaminants and the substrate while maintaining process simplicity.
3Productivity
If the passage width between the inner cup and exhaust tube is increased to improve air flow, then air evacuation is enhanced, but the vortex generation is exacerbated due to the larger mismatch with the outer cup space
Solution Approach 1:
The patent applies local quality by optimizing the width of the second passage (between inner cup and exhaust tube) to be smaller than the first passage. This local adjustment at the exhaust tube interface prevents vortex formation by creating a controlled flow transition, while still maintaining adequate air evacuation efficiency through proper exhaust tube positioning and sizing.
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 design enhances substrate treating efficiency by preventing vortices and backflows, ensuring uniform liquid film thickness and minimizing contaminant re-adsorption, thereby improving the overall processing quality.
Implementation Method 1
an air flow 84 on the surface of the substrate W flows from the center of the substrate W toward the edge thereof along the rotating direction of the substrate W by the centrifugal force
Implementation Method 2
the outer cup including a protrusion provided at a side wall... creates equal passage widths for airflow to prevent vortex formation
Implementation Method 3
a pressure adjustment member, which creates equal passage widths for airflow to prevent vortex formation and ensure smooth exhaust
Data Source
AI summary
An apparatus for treating a substrate, the apparatus comprising: a treating container having an inner space; a support unit supporting and rotating the substrate in the inner space; and an exhaust unit exhausting an air flow in the inner space, wherein the treating container includes an outer cup providing the inner space; and an inner cup disposed at the inner space and spaced apart from the outer cup, and wherein the outer cup has a protrusion at a side wall thereof.