Lithographic Light-Shielding Plate Arc Edge Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithographic methods for semiconductor device manufacturing using flip-chip implementation face issues with dust generation and dirt adherence due to light-shielding plates, leading to defects in semiconductor devices.
Innovation Solution
A lithographic apparatus with a light-shielding plate having an arc or polygon edge that overlaps with a circular boundary on the substrate, positioned inside the substrate's periphery, rotates and linearly moves to block light from the outer peripheral region, preventing dust accumulation and ensuring accurate pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light-shielding plate is placed on the wafer to block light during exposure, then light blocking is effective, but dust is generated during loading/unloading and dirt adheres to the wafer causing defects
Solution Approach 1:
The patent introduces a light-shielding plate positioned at an intermediate location between the light source and the wafer's outer peripheral region. This mediator blocks light from reaching the outer peripheral area without requiring direct contact with the wafer surface, thereby preventing both light contamination and dust generation on the wafer.
Solution Approach 2:
The light-shielding plate is positioned in a different spatial dimension (above the wafer surface at a predetermined distance) rather than directly on the wafer. This dimensional separation allows the plate to block light effectively while avoiding contact with the wafer, thus eliminating dust generation during loading and unloading operations.
2Object-affected harmful factors
If four light-shielding plates are driven in x and y directions to define irradiation regions, then light blocking coverage is improved, but device complexity increases with eight driving units and dust is generated upon driving
Solution Approach 1:
The patent merges the functions of multiple light-shielding plates into a single integrated plate structure. This single plate can define irradiation regions for multiple quadrants simultaneously, eliminating the need for separate driving units for each plate and reducing overall system complexity while maintaining comprehensive light blocking coverage.
Solution Approach 2:
The light-shielding plate is designed with universal functionality to serve multiple purposes: it can define irradiation regions for different quadrants, block light from various directions, and operate without requiring separate driving mechanisms for each function. This multi-functionality reduces the total number of components and simplifies the overall system.
3Manufacturing precision
If a light-shielding plate is positioned close to the wafer for effective light blocking, then light blocking precision is improved, but dust generation and dirt adherence increase
Solution Approach 1:
The light-shielding plate acts as an intermediary element positioned at an optimal distance from the wafer surface. This intermediate positioning allows the plate to effectively block light and define precise irradiation regions while maintaining sufficient separation to prevent dust generation and dirt adherence on the wafer during operation.
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 solution effectively prevents light from reaching the outer peripheral regions of the substrate, reducing dust-related defects and improving the precision of pattern transfer in semiconductor device manufacturing without compromising processing efficiency.
Implementation Method 1
a light-shielding plate which includes, on an edge thereof, an arc overlapping with a circular boundary line that defines a region, onto which the pattern is transferred, on the substrate and is located inside an outer periphery of the substrate at a predetermined distance therefrom, and blocks the light to prevent the light from being incident on an outer peripheral region located outside the circular boundary line on the substrate
Data Source
AI summary
A lithographic apparatus includes: a light-shielding plate which includes, on an edge thereof, an arc overlapping with a circular boundary line that defines a region onto which the pattern is transferred and is located inside an outer periphery of a substrate, and blocks the light to prevent the light from being incident on an outer peripheral region located outside the circular boundary line; a first driving unit which rotates the light-shielding plate about an axis parallel to an optical axis of the irradiation system; and a second driving unit which linearly drives the light-shielding plate within a plane perpendicular to the optical axis.