Facet Mirror EUV Beam Width Adjustment for Reticle Pattern Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In EUV lithography, the extreme ultraviolet (EUV) radiation beam often covers areas larger than the intended layout patterns, leading to extra coverage that affects neighboring dies and critical dimensions, and current solutions like reticle-masks (REMA) block this extra coverage but reduce the utilization efficiency and throughput of the exposure device.
Innovation Solution
The use of facet mirrors controlled by a beam width adjuster system to precisely adjust the coverage area of the EUV radiation beam, eliminating the need for REMAs by concentrating the beam and optimizing its projection onto the photo mask, thereby increasing the intensity per unit area and reducing exposure time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the EUV radiation beam covers a larger area than the layout patterns, then the coverage area is increased, but the utilization efficiency of the EUV radiation beam is reduced
Solution Approach 1:
The patent implements dynamic adjustment of the EUV radiation beam width using facet mirrors that can be moved relative to each other. The beam width is dynamically adjusted to match the layout pattern dimensions, allowing the system to optimize between coverage area and energy utilization efficiency based on the specific pattern being exposed. This dynamic control eliminates the need for fixed beam widths and enables precise matching to varying pattern requirements.
Solution Approach 2:
The patent changes the physical parameter of beam width by moving facet mirrors to different positions. By adjusting the relative positions of the facet mirrors, the beam width parameter is modified to precisely match the layout pattern size, thereby maximizing energy utilization efficiency while maintaining appropriate coverage area. This parameter adjustment resolves the contradiction between covering sufficient area and avoiding energy waste.
2Manufacturing precision
If reticle-masks (REMA) are used to block extra coverage of the EUV radiation beam, then the critical dimension accuracy is improved, but the throughput of the exposure device is reduced
Solution Approach 1:
The patent extracts and removes the REMA component from the system by implementing alternative beam width control through facet mirror adjustment. Instead of using physical blocking structures (REMA) to achieve critical dimension accuracy, the system directly controls the beam width to match the layout patterns, eliminating the need for additional blocking components and the throughput penalties they impose.
Solution Approach 2:
The patent replaces the static blocking approach of REMA with dynamic beam width adjustment using movable facet mirrors. This dynamic control allows the beam width to be precisely matched to the layout pattern dimensions in real-time, achieving critical dimension accuracy without the need for physical blockers that would reduce throughput. The system adapts dynamically rather than relying on fixed blocking structures.
3Area of stationary object
If the EUV radiation beam covers areas outside the layout patterns, then the illumination area is increased, but the exposure time is extended
Solution Approach 1:
The patent changes the beam width parameter by adjusting facet mirror positions to precisely match the layout pattern dimensions. This parameter adjustment ensures that the illumination area is optimized to cover exactly the required pattern area without extension beyond the patterns, thereby preventing exposure time extension while maintaining appropriate illumination coverage.
Solution Approach 2:
The patent implements dynamic beam width adjustment that adapts to different layout pattern sizes. By dynamically controlling the beam width to match the specific pattern being exposed, the system ensures that the illumination area is neither excessive nor insufficient, optimizing exposure time for each specific pattern configuration rather than using a fixed conservative beam width.
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
This approach enhances the throughput and efficiency of the EUV exposure tool by ensuring no extra coverage is wasted, allowing for more precise patterning and increased EUV radiation utilization without the need for REMAs, thus improving the critical dimension accuracy and reducing exposure time.
Implementation Method 1
transmitting the first EUV radiation beam to a first mirror that comprises two or more first facets, directing a second EUV radiation beam reflected from the first mirror to a second mirror that comprises two or more second facets
Data Source
AI summary
In a method of pattern formation information including a pattern size on a reticle is received. A width of an EUV radiation beam is adjusted in accordance with the information. The EUV radiation beam is scanned on the reticle. A photo resist layer is exposed with a reflected EUV radiation beam from the reticle. An increase of intensity per unit area of the EUV radiation beam on the reticle after the adjusting the width is greater when the width before adjustment is W1 compared to an increase of intensity per unit area of the EUV radiation beam on the reticle after the adjusting the width when the width before adjustment is W2 when W1>W2.