Substrate Processing Guard with Segmented Inert Gas Supply
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in promptly reducing oxygen concentration and humidity within the processing chamber, leading to potential pattern collapse during the spin drying step due to high surface tension of rinse liquids like water, and the existing gas supplying apparatuses are obstructed, making it difficult to achieve effective reduction.
Innovation Solution
A substrate processing apparatus with a guard surrounding the substrate holding unit and facing member, featuring a processing liquid supplying nozzle extending from the guard's inner wall and an inert gas supplying unit to isolate and replace the atmosphere within the formed space, allowing for reduced oxygen concentration and humidity, enabling efficient drying of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gas supplying apparatus with a gas hood is used to reduce oxygen concentration and humidity, then the atmosphere can be controlled, but the output shaft of the motor obstructs the gas hood, preventing it from approaching the substrate surface sufficiently
Solution Approach 1:
The gas supplying apparatus is divided into a gas hood and a gas supply unit. The gas supply unit can be positioned independently closer to the substrate surface without being obstructed by the motor output shaft, while the gas hood remains in its original position for atmosphere control.
Solution Approach 2:
A separate gas supply unit acts as an intermediary between the gas hood and the substrate surface. This unit delivers the inert gas directly to the substrate surface without being blocked by the motor output shaft, enabling effective atmosphere control at the critical interface.
2Productivity
If the gas hood is positioned close to the substrate surface for effective atmosphere control, then oxygen concentration and humidity can be reduced promptly, but the motor output shaft prevents sufficient approach
Solution Approach 1:
The gas supplying apparatus is segmented into a stationary gas hood and a movable gas supply unit. This allows the gas supply unit to be positioned close to the substrate surface for rapid atmosphere control during drying, while the gas hood remains in its original position, avoiding interference from the motor output shaft.
Solution Approach 2:
The gas supply unit is designed to be movable or adjustable, allowing it to dynamically position itself close to the substrate surface when needed for rapid drying, while the overall structure remains compatible with the existing motor output shaft configuration.
3Ease of manufacture
If water is used as a rinse liquid, then it is effective for cleaning, but its high surface tension causes pattern collapse during spin drying
Solution Approach 1:
The surface tension parameter of the rinse liquid is changed by replacing water with IPA (isopropyl alcohol). IPA has lower surface tension than water, which prevents pattern collapse during spin drying while maintaining effective cleaning capability.
Solution Approach 2:
An inert gas atmosphere is supplied to the processing chamber during the drying process. This inert environment prevents oxidation of the pattern by oxygen dissolved in the IPA and facilitates rapid evaporation of the IPA, completing the drying process without pattern collapse.
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 apparatus effectively reduces oxygen concentration and humidity between the substrate and facing member, facilitating prompt drying and preventing pattern collapse by allowing the processing liquid nozzle to approach the substrate closely, ensuring efficient evaporation of low surface tension liquids like IPA.
Implementation Method 1
an inert gas supplying unit that supplies an inert gas to the space to replace an atmosphere inside the space by the inert gas
Implementation Method 2
a processing liquid supplying nozzle that extends from an inner wall of the guard so as to be disposed inside the space in a state where the space is formed and supplies the processing liquid to the upper surface of the substrate
Implementation Method 3
supply isopropyl alcohol (IPA), which is a low surface tension liquid of lower surface tension than water, to the substrate to replace the water, which has entered into the interior of the pattern
Implementation Method 4
a spin drying step is performed to remove the rinse liquid on the substrate
Data Source
AI summary
A guard that receives a processing liquid removed off a substrate, is disposed so as to surround a substrate holding unit and a facing member in plan view. The guard forms, together with the substrate and the facing member having a facing surface facing an upper surface of the substrate, a space isolated from an ambient atmosphere. An inert gas supplying unit supplies an inert gas to the space to replace an atmosphere inside the space by the inert gas. A processing liquid supplying nozzle, which extends from an inner wall of the guard so as to be disposed inside the space in a state where the space is formed, supplies the processing liquid to the upper surface of the substrate.