Lithographic Substrate Support Reconditioning via Micro-Fracturing
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Solution Overview
Problem
Existing substrate support cleaning tools for lithographic apparatuses can lead to increased Wafer Load Grid (WLG) errors and overlay issues due to contamination and surface smoothing, which affect the flatness and alignment of semiconductor wafers during patterning processes.
Innovation Solution
A treatment tool with a reconditioning surface that is rougher and harder than the substrate support projections, causing micro-fracturing and creating spikes on the surface to maintain or reduce WLG, thereby improving the flatness and reducing overlay errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a treatment tool is moved over the substrate support to remove contamination, then the cleanliness of the substrate support is improved, but the Wafer Load Grid (WLG) errors increase
Solution Approach 1:
The treatment tool changes the surface parameters of the substrate support by creating controlled micro-fractures and spikes through mechanical interaction. This transforms the surface topology to reduce contact area and friction, thereby reducing WLG errors while maintaining cleanliness.
Solution Approach 2:
The treatment tool utilizes vibrational motion during contact with the substrate support projections. This vibration facilitates effective contamination removal while controlling the mechanical interaction to prevent excessive smoothing that would increase WLG errors.
2Shape
If the treatment tool smooths the substrate support surface, then the flatness is improved, but the friction increases leading to higher WLG errors
Solution Approach 1:
The treatment creates localized surface features (micro-fractures and spikes) at specific contact points rather than uniform smoothing. This local modification reduces friction by creating point contacts while maintaining overall flatness for alignment purposes.
Solution Approach 2:
The mechanical action of the treatment tool on the projections creates rounded or spiked surface features rather than perfectly flat surfaces. This curvature modification reduces contact area and friction between the substrate and substrate support.
3Manufacturing precision
If the treatment tool is made harder than the substrate support, then the reconditioning effectiveness is improved, but the risk of damaging the substrate support increases
Solution Approach 1:
The treatment tool material is selected with specific hardness parameters greater than the substrate support material. This hardness differential enables effective reconditioning through controlled micro-fracturing while the tool's design distributes forces to prevent catastrophic damage.
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 tool effectively reconditions the substrate support surfaces, reducing friction and maintaining or lowering the WLG, ensuring precise alignment and reducing overlay errors during multiple pattern projections.
Implementation Method 1
A treatment tool with a reconditioning surface that is rougher and harder than the substrate support projections, causing micro-fracturing and creating spikes on the surface
Data Source
AI summary
A treatment tool for reconditioning the top surfaces of a plurality of projections of a substrate support in a lithographic tool. The treatment tool includes a reconditioning surface which is rough relative to smoothed top surfaces of the projections and which reconditioning surface has material harder than that of the material of the top surfaces of the projections. A reconditioning method involves causing an interaction between the reconditioning surface of the treatment tool and the top surfaces of the projections of the substrate support, so as to leave these top surfaces rougher than they were prior to the interaction.