Multi-beam Lithography Mask Data Preparation
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Solution Overview
Problem
Current optical lithography techniques face challenges in accurately transferring patterns with features smaller than the light wavelength used, requiring complex OPC features like serifs and SRAFs, which increase mask complexity and computation time, and EUV lithography demands higher precision due to mid-range scattering effects, necessitating more precise mask data preparation.
Innovation Solution
A method for fracturing single-beam charged particle beam shots into multi-beam shots, using calculated pattern information to generate multi-beam exposure information, which allows for more efficient and accurate pattern formation on reticles by optimizing shot overlap and dosage, thereby reducing critical dimension variation and edge slope.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If optical lithography is used to transfer patterns with features smaller than the light wavelength, then pattern transfer capability is improved, but mask complexity and computation time increase due to required OPC features
Solution Approach 1:
The patent divides the mask data preparation process into multiple passes, where each pass writes a subset of the final pattern. This segmentation allows the system to build up complex patterns incrementally, reducing the complexity of individual mask writing operations while achieving the required pattern fidelity for sub-wavelength features
Solution Approach 2:
The patent performs preliminary mask writing passes that establish base patterns and structures before final pattern transfer. These preliminary actions create a foundation that simplifies subsequent writing operations and reduces the computational burden of generating OPC features like serifs and SRAFs
2Manufacturing precision
If optical lithography uses OPC features like serifs and SRAFs to achieve sub-wavelength pattern transfer, then pattern accuracy is improved, but computation time increases
Solution Approach 1:
The patent segments the pattern writing into multiple passes, distributing the computational workload across different time periods. Each pass handles a portion of the pattern with optimized OPC features, reducing peak computation time while maintaining overall pattern accuracy
Solution Approach 2:
The patent applies OPC features selectively based on pattern requirements rather than uniformly across all features. This partial application of OPC (such as serifs and SRAFs) maintains pattern accuracy where needed while reducing unnecessary computation on features that don't require complex corrections
3Manufacturing precision
If EUV lithography is used for higher precision pattern transfer, then manufacturing precision is improved, but mid-range scattering effects increase complexity in mask data preparation
Solution Approach 1:
The patent performs preliminary simulation and calculation of scattering effects before actual mask writing. This preliminary action characterizes the mid-range scattering behavior of the specific EUV system, allowing the mask data preparation to compensate for these effects systematically rather than dealing with them during the writing process
Solution Approach 2:
The patent adjusts mask writing parameters such as beam energy, shot size, and overlap based on the characterized scattering effects. These parameter changes are optimized to minimize the impact of mid-range scattering while achieving the required pattern precision for EUV lithography
4Device complexity
If single-beam charged particle beam writing is used for pattern formation, then device complexity is reduced, but writing speed decreases
Solution Approach 1:
The patent implements multi-pass writing where the beam continuously writes patterns across the mask surface in systematic passes. This continuous operation maximizes the utilization of the single beam, reducing idle time and maintaining high writing speed despite the sequential nature of single-beam 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
This approach enhances the accuracy and efficiency of pattern transfer, reducing critical dimension variation and edge roughness, allowing for the creation of more precise reticles with fewer errors, and supports the use of multi-beam writers in existing production environments.
Implementation Method 1
a charged particle beam writer is used to write patterns on a mask or reticle
Data Source
AI summary
A method for fracturing or mask data preparation is disclosed in which a plurality of single-beam charged particle beam shots is used to create a plurality of multi-beam shots, where multi-beam exposure information is determined for each of the single-beam shots, and then the resulting multi-beam exposure information is used to generate a set of multi-beam shots. Additionally, a method for fracturing or mask data preparation is disclosed in which a plurality of single-beam shots is used to generate a set of multi-beam shots by calculating an image which the single-beam shots would form on a surface.