Lithographic Apparatus Contaminant Trap Surface Texture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithographic apparatuses face contamination issues due to dust or other contaminants on patterning devices, which can lead to imaging errors and reduced yield, especially with EUV radiation systems where DUV radiation also causes contrast reduction.
Innovation Solution
A contaminant trap surface texture with recesses is introduced, having dimensions less than or equal to 2 μm in width and greater than or equal to 1 μm in depth, designed to trap particles and reduce specular reflection of DUV radiation, enhancing particle attachment and absorption while minimizing DUV radiation impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a smooth surface is used on patterning device components, then specular reflection of DUV radiation is reduced, but contaminant particle trapping is insufficient
Solution Approach 1:
The surface is given different local properties: recesses with dimensions less than or equal to 2 μm provide particle trapping functionality, while the overall surface geometry maintains low specular reflection of DUV radiation. This local differentiation resolves the contradiction between particle trapping and radiation reflection reduction.
Solution Approach 2:
The surface is structured with recesses forming a porous-like texture that enables particle trapping through physical confinement. The recess dimensions are specifically controlled to trap particles while the surface as a whole maintains optical properties that minimize DUV radiation specular reflection.
2Reliability
If recess dimensions are made very small to trap smaller particles, then particle trapping effectiveness improves, but manufacturing precision requirements increase
Solution Approach 1:
The recess dimensions are optimized within specific ranges (width ≤ 2 μm, depth ≥ 1 μm) to achieve effective particle trapping. These parameter specifications balance trapping effectiveness with manufacturability, avoiding excessively small dimensions that would be difficult to produce while still capturing the required particle size range.
3Reliability
If the surface is treated to form deep recesses for particle trapping, then contaminant attachment improves, but surface area increases which may affect other performance aspects
Solution Approach 1:
The surface treatment applies recesses with depth greater than or equal to 1 μm to achieve effective particle trapping. The recess depth is sufficient to trap particles but not excessively deep to cause disproportionate surface area increase, maintaining a balance between trapping effectiveness and surface area management.
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 surface texture effectively traps contaminants and reduces DUV radiation reflection, preventing imaging errors and maintaining high yield by ensuring cleaner patterning devices and improved contrast in EUV lithographic processes.
Implementation Method 1
a contaminant trap surface texture provided with recesses configured to trap contaminant particles
Implementation Method 2
reduce specular reflection of DUV radiation (which is a spurious component of EUV generation)
Data Source
AI summary
A component of a lithographic apparatus, the component having a contaminant trap surface provided with recesses configured to trap contaminant particles and to reduce specular reflection of DUV radiation. The recesses can have at least one dimension less than or equal to about 2 μm, desirably less than 1 μm.