Rotating Substrate Stage With Edge Protrusions for Uniform Freeze-Cleaning
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Solution Overview
Problem
The existing freeze-cleaning method for substrates, such as semiconductor wafers and photolithography masks, faces challenges in maintaining uniform temperature distribution, particularly at the peripheral edges, leading to reduced contaminant removal efficiency due to increased heat input from the external atmosphere.
Innovation Solution
A substrate treatment device is designed with a rotating placement stand equipped with protrusions along the substrate's boundary, which restricts the flow of cooling gas and liquid, ensuring even temperature distribution and prolonged contact time for effective cooling and contaminant removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If cooling gas is supplied to the substrate surface for freeze-cleaning, then contaminant removal is achieved, but temperature distribution becomes non-uniform with higher temperature at peripheral edges
Solution Approach 1:
The patent applies local quality by providing a higher concentration of cooling gas flow to the peripheral edge regions of the substrate compared to the central region. The side wall structure with its opening facing the substrate periphery creates a localized cooling zone that compensates for the higher heat input at the edges, thereby achieving uniform temperature distribution across the substrate surface.
Solution Approach 2:
The side wall acts as an intermediary structure that redirects and concentrates cooling gas flow to the peripheral regions. By positioning the side wall between the cooling gas source and the substrate periphery, it mediates the cooling process to ensure adequate cooling at the edges without affecting the central region excessively.
2Temperature
If cooling gas flow rate is increased to improve peripheral cooling, then temperature uniformity improves, but heat input from external atmosphere increases
Solution Approach 1:
The side wall functions as a protective barrier that shields the cooling gas flow from direct exposure to the external atmosphere. This structural enclosure reduces heat input from external air while maintaining controlled cooling gas flow to the substrate periphery, achieving temperature uniformity without excessive energy loss.
3Ease of operation
If the substrate periphery is exposed to external atmosphere, then access for processing is improved, but cooling efficiency decreases due to heat input
Solution Approach 1:
The side wall structure segments the cooling zone from the external atmosphere, creating a dedicated cooling channel along the substrate periphery. This segmentation allows the cooling process to occur in a controlled environment while maintaining substrate accessibility from other directions.
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 device enhances the cooling efficiency at the peripheral edges and corners of the substrate, improving the removal ratio of contaminants by maintaining a uniform in-plane temperature and preventing external air from interfering with the cooling process.
Implementation Method 1
cooling gas is supplied into a space between a placement stand and a back surface of the substrate
Implementation Method 2
the water film is frozen by the cooling gas supplied to the substrate. When the water film freezes and an ice film is formed
Implementation Method 3
pure water is supplied to the ice film to melt the ice film, and contaminations are removed from the surface of the substrate together with the pure water
Data Source
AI summary
According to one embodiment, q substrate treatment device includes a placement stand, a plurality of support portions, a cooling part, a liquid supplier, and at least one protrusion. The placement stand has a plate shape, and is configured to rotate. The support portions are provided on one surface of the placement stand and configured to support a substrate. The cooling part is configured to supply a cooling gas into a space between the placement stand and a back surface of the substrate supported by the support portions. The liquid supplier is configured to supply a liquid onto a surface of the substrate. At least one protrusion is provided on the one surface of the placement stand and extends along a boundary line of a region where the substrate is provided in a plan view.