Freeze-Cleaning Substrate Stage With Frost-Blocking Holders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing apparatuses face issues with unnecessary freezing around the substrate during freeze cleaning, leading to potential malfunction and reduced effectiveness of the cleaning process.
Innovation Solution
A substrate processing apparatus with a rotatable stage, holders that surround the substrate's peripheral edge, and a cooling gas supply system to control freezing, along with liquid supplies to manage frost formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cooling gas is supplied to the space between the stage and the substrate to perform freeze cleaning, then the contaminants are effectively removed from the substrate surface, but unnecessary freezing and frost generation occur around the substrate due to moisture in the atmosphere
Solution Approach 1:
The holder is designed with different thermal properties for different regions: the portion facing the substrate is made of heat-resistant material to prevent freezing, while the portion facing the cooling gas can be cooled. This local differentiation allows the holder to withstand the cooling process without causing unnecessary freezing around the substrate.
Solution Approach 2:
The holder acts as an intermediary between the cooling gas and the substrate. By positioning the holder to block the cooling gas from directly contacting the substrate perimeter, and by making the holder's substrate-facing surface heat-resistant, it mediates the cooling process to prevent harmful freezing while maintaining effective cleaning.
2Object-affected harmful factors
If the holder is made of heat-resistant material to prevent freezing, then unnecessary freezing is suppressed, but the holder cannot effectively transmit cooling to the substrate for freeze cleaning
Solution Approach 1:
The holder is segmented into functionally distinct portions: a heat-resistant portion facing the substrate to prevent freezing, and a coolable portion facing the cooling gas to transmit cold. This segmentation allows each portion to perform its specific function optimally without compromising the other.
Solution Approach 2:
Different portions of the holder are assigned different thermal characteristics. The substrate-facing surface uses heat-resistant material to prevent freezing, while other portions can be cooled by the cooling gas. This local quality differentiation resolves the contradiction between preventing freezing and transmitting cooling.
3Object-affected harmful factors
If the holder surrounds the substrate to block cooling gas, then unnecessary freezing is prevented, but the freeze cleaning process becomes less effective
Solution Approach 1:
The holder is designed with spatially differentiated properties: portions that block the cooling gas to prevent frost formation, and portions that allow cooling to reach the substrate for effective cleaning. The substrate-facing surface is specifically designed to be heat-resistant while still allowing controlled cooling.
Solution Approach 2:
The holder serves as a selective intermediary that blocks the cooling gas from causing harmful freezing around the substrate perimeter, while still permitting the cooling process to effectively reach the substrate surface for contaminant removal.
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 suppresses unnecessary freezing around the substrate, preventing apparatus malfunction and enhancing the efficiency of the freeze cleaning process.
Implementation Method 1
a cooler capable of supplying a cooling gas to a space between the stage and the substrate
Implementation Method 2
a liquid such as pure water is supplied to the surface of the substrate first to form a liquid film. Then, a cooling gas is supplied to the side of the surface of the substrate to freeze the liquid film
Implementation Method 3
Subsequently, a liquid such as pure water is supplied to the frozen film to melt the frozen film, so that the contaminants are removed from the surface of the substrate together with the liquid
Data Source
AI summary
According to one embodiment, a substrate processing apparatus includes: a stage rotatable around a central axis; a plurality of holders provided on the stage to hold a substrate; a cooler capable of supplying a cooling gas to a space between the stage and the substrate; and a liquid supply capable of supplying a liquid to a surface of the substrate on an opposite side to the stage. When holding the substrate, each of the plurality of holders moves toward the central axis along a surface of the stage so as to surround a peripheral edge of the substrate and the space between the stage and the substrate.