Exposure System Beam Shaping for Complex IC Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current exposure systems for integrated circuit fabrication face challenges in forming complex photomask patterns with varying shapes and irregular line widths, which are necessary due to decreasing design rules, as they are limited in shaping and controlling electron beams effectively.
Innovation Solution
The exposure system employs a beam generator and beam shapers with a shift screen mechanism, allowing for the precise control and shaping of electron beams into various shapes by overlapping apertures and using a combination of tetragonal and L-shaped exposures, enabling the formation of complex patterns without the need for extensive division of exposures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional exposure systems are used to form complex photomask patterns, then the basic exposure function is achieved, but the ability to form various shapes and control electron beams effectively is limited
Solution Approach 1:
The exposure system divides the beam shaping function into multiple independent aperture plates, each with specific aperture patterns. By combining and overlaying patterns from different plates, the system can form complex shapes such as L-shaped, U-shaped, and other irregular patterns that cannot be achieved with a single aperture, thereby enhancing adaptability without requiring complete redesign of the beam control system
Solution Approach 2:
The patent introduces a new dimension of control by using multiple aperture plates positioned at different locations in the beam path. Instead of relying solely on single-plane aperture masking, the system utilizes the spatial dimension of multiple plates to create complex three-dimensional beam patterns, enabling versatile pattern formation while maintaining relatively simple individual plate designs
2Productivity
If design rules are decreased to increase integration density, then higher integration density is achieved, but the complexity of forming various photomask pattern shapes increases
Solution Approach 1:
By segmenting the pattern formation process into multiple aperture plates with simple geometric patterns, the system can efficiently form complex patterns required for decreased design rules. Each plate handles a specific portion of the pattern, and their combination achieves the desired complex shapes without requiring overly complex individual components, thus supporting higher integration density
Solution Approach 2:
The system employs movable aperture plates that can be positioned and adjusted dynamically during the exposure process. This dynamic capability allows the same hardware configuration to adapt to different pattern requirements arising from decreased design rules, maintaining flexibility and reducing the need for specialized equipment for each pattern type
3Manufacturing precision
If extensive division of exposures is used to form complex patterns, then pattern precision is improved, but exposure time and throughput are reduced
Solution Approach 1:
The patent merges multiple pattern formation operations into a single exposure step by using multiple aperture plates simultaneously. Instead of performing separate exposures for different pattern portions, the system combines patterns from multiple plates in one exposure event, thereby maintaining high pattern precision while significantly improving throughput and reducing total exposure time
Data Source
AI summary
Exposure systems include a beam generator, which is configured to irradiate source beams in a direction of an object to be exposed by the source beams, along with first and second beam shapers. The first beam shaper, which is disposed proximate the beam generator, has a first aperture therein positioned to pass through the source beams received from the beam generator. The second beam shaper is disposed proximate the first beam shaper. The second beam shaper includes a plate having a second aperture therein, which is positioned to receive the source beams that are passed through the first aperture of the first beam shaper. The second beam shaper further includes a first actuator and a first shift screen mechanically coupled to the first actuator.