Bernoulli Substrate Holder With Division Plate for Liquid Adhesion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate processing methods using Bernoulli chucks result in processing liquids adhering to the lower surface of substrates due to negative pressure and collision with protrusions, leading to particulate matter dispersion.
Innovation Solution
A substrate processing apparatus with a substrate holder that includes a base part, support pins, a gas supply part, and a division plate to create an outward airflow, suppressing liquid adhesion by the Bernoulli effect and utilizing a division plate to redirect liquid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Bernoulli chuck is used to hold the substrate, then the substrate can be securely held in position, but the negative pressure causes processing liquid to be sucked to the lower surface of the substrate
Solution Approach 1:
The base part is divided into a liquid discharge part and a gas discharge part, which are spatially separated. The liquid discharge part discharges processing liquid that has flowed to the lower surface, while the gas discharge part maintains the Bernoulli effect for substrate holding. This segmentation allows independent optimization of substrate holding and liquid discharge functions.
Solution Approach 2:
A liquid discharge port is introduced as an intermediary element between the lower surface of the substrate and the external environment. This port provides a controlled path for processing liquid to exit, preventing liquid accumulation and adhesion to the lower surface while maintaining the negative pressure field for secure substrate holding.
2Manufacturing precision
If protrusions such as centering pins are provided on the substrate holder, then the substrate can be centered and held, but processing liquid collides with these protrusions and produces particulate matter that adheres to the lower surface
Solution Approach 1:
The harmful effect of liquid collision with protrusions is extracted and addressed by providing a dedicated liquid discharge path. The liquid discharge port is positioned to receive and remove processing liquid before it can collide with centering pins or other protrusions, thereby preventing particulate matter generation while maintaining centering functionality.
Solution Approach 2:
The processing liquid that would otherwise cause harm by colliding with protrusions is converted into a beneficial flow that is directed through the liquid discharge port. The negative pressure field that causes liquid to flow to the lower surface is now utilized to actively draw liquid through the discharge port, transforming a harmful effect into a useful liquid removal mechanism.
3Device complexity
If the substrate holder has a simple structure, then the device complexity is reduced, but it cannot effectively prevent processing liquid from adhering to the lower surface
Solution Approach 1:
The base part is designed to perform multiple functions: it provides structural support for the substrate holder, creates the negative pressure field for substrate holding, and discharges processing liquid through integrated discharge ports. The gas discharge part and liquid discharge part work together within a single base structure, achieving complex functionality without proportionally increasing device complexity.
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
Effectively prevents processing liquid from adhering to the lower surface of substrates by creating a pressure drop and redirecting liquid flow, enhancing processing efficiency and cleanliness.
Implementation Method 1
a gas supply part that sends out a gas to a space between the lower surface of the substrate and the base surface of the base part to form an airflow that flows radially outward
Implementation Method 2
The substrate holder produces a pressure drop in a space between the substrate and the base part by a Bernoulli effect resulting from the airflow to adsorb the substrate
Data Source
AI summary
In a substrate holder, a gas supply part sends out a gas to the space between the lower surface of a substrate and a base surface of a base part to form a radially outward airflow. A division plate is arranged radially outward of the outer peripheral edge of the substrate on the base surface of the base part to surround the substrate. The inner peripheral edge of the division plate and the outer peripheral edge of the substrate face each other in the radial direction with a space in between. The upper surface of the division plate is located below or at the same position in the up-down direction as the upper surface of the substrate. An annular passage is provided between the lower surface of the division plate and the base surface of the base part.