Immersion Lithography Shield Module for Wafer Edge Particle Contamination
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Solution Overview
Problem
In immersion photolithography, the edge of the wafer often accumulates resist particles that can flake off and contaminate the system, leading to pattern defects and distortions due to the solvent removing the edge resist, causing particles to be uncovered and potentially contaminating the immersion lithography system.
Innovation Solution
A shield module is implemented around the wafer edge, comprising a body portion and a cover portion that can be adjusted to shield the area, made of materials like stainless steel or quartz, with optional openings for hydrodynamic control, to prevent particles from entering the immersion fluid and contaminating the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If immersion lithography is used to achieve higher numerical aperture and improved resolution, then manufacturing precision is improved, but particles generated at the wafer edge during spin coating can contaminate the system and cause pattern defects
Solution Approach 1:
A shield module is introduced as an intermediary component between the wafer edge and the immersion fluid. The shield module includes a body portion positioned at the wafer edge and a cover portion that can be adjusted to shield the area, preventing particles from the edge from entering the immersion fluid and contaminating the system.
Solution Approach 2:
The shield module is divided into separate functional sections: a body portion that is positioned at the wafer edge and a cover portion that can be independently adjusted. This segmentation allows the shield module to adapt to different wafer sizes and edge conditions while maintaining the core function of particle containment.
2Device complexity
If the wafer edge is left unshielded during processing, then device complexity is reduced, but particles accumulate and flake off causing system contamination and pattern defects
Solution Approach 1:
The cover portion of the shield module is designed to be adjustable, allowing it to be dynamically positioned to shield the wafer edge during processing. This dynamic capability enables the system to adapt to different processing conditions and wafer configurations while maintaining particle containment effectiveness.
Solution Approach 2:
The shield module provides localized protection specifically at the wafer edge area where particle generation occurs, rather than requiring comprehensive shielding of the entire wafer. This local quality approach concentrates the shielding function where it is most needed, reducing overall device complexity while maintaining system reliability.
Data Source
AI summary
Immersion lithography apparatus and method using a shield module are provided. An immersion lithography apparatus including a lens module having an imaging lens, a substrate table positioned beneath the lens module and configured for holding a substrate for processing, a fluid module for providing an immersion fluid to a space between the lens module and the substrate on the substrate table, and a shield module for covering an edge of the substrate during processing.