Microlens Field Curvature Corrector for Multi-Beam Blur Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multi-electron-beam systems face challenges in correcting field curvature blur, which degrades image resolution, increases arcing risks, and fails to correct asymmetrical blurs due to optical column misalignments, limiting throughput and resolution in semiconductor inspection.
Innovation Solution
A multi-beam electron imaging system with a field curvature corrector that individually corrects field curvature blur using a conductive plate and microlens array, applying independent voltages to each beamlet to minimize spherical aberration and arcing risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If field curvature blur is corrected using collectively corrected methodology, then throughput is improved, but image resolution degrades due to large spherical aberration blurs
Solution Approach 1:
The patent divides the field curvature correction into individual beamlet-level corrections using separate correctors for each beamlet, rather than collective correction. This segmentation allows each beamlet to be corrected independently, maintaining image resolution while enabling parallel processing that improves throughput.
Solution Approach 2:
The patent applies local quality by providing customized correction for each beamlet based on its specific field curvature characteristics. Each beamlet receives tailored correction parameters, allowing optimal resolution maintenance for each individual beamlet while the overall system achieves high throughput through parallel operation.
2Manufacturing precision
If high FC correction voltages are applied, then field curvature blur is corrected, but arcing risks increase
Solution Approach 1:
The patent employs dynamic voltage adjustment for each beamlet's field curvature corrector, allowing the system to apply only the necessary correction voltage for each individual beamlet rather than using uniformly high voltages. This dynamic approach maintains effective field curvature correction while minimizing arcing risks through optimized voltage levels.
3Device complexity
If collectively corrected methodology is used, then system complexity is reduced, but asymmetrical FC blurs due to optical column misalignments cannot be corrected
Solution Approach 1:
The patent changes the correction parameters individually for each beamlet, allowing the system to adapt to asymmetrical field curvature blurs caused by optical column misalignments. By adjusting parameters such as correction voltage and focal length for each beamlet separately, the system can compensate for misalignments while maintaining manageable complexity through automated parameter optimization.
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 system maintains high resolution while improving throughput by effectively correcting both symmetrical and asymmetrical field curvature blurs, reducing spherical aberration and arcing risks, and enhancing inspection efficiency.
Implementation Method 1
a microlens array, wherein the microlens array includes a plurality of microlenses formed on an insulative plate
Implementation Method 2
a conductive plate, wherein the conductive plate includes a plurality of holes arranged in a hexagonal array
Data Source
AI summary
A multi-electron-beam (MEB) imaging system may include a field curvature corrector for individually correcting electron beamlets for field curvature blur by individually addressing microlenses of the field curvature corrector. The field curvature corrector may include a conductive plate, wherein the conductive plate includes a plurality of holes arranged in a hexagonal array. The field curvature corrector may include a microlens array, wherein the microlens array includes a plurality of microlenses formed on an insulative plate, wherein the plurality of microlenses are arranged in a hexagonal pattern to match the hexagonal pattern of the holes of the conductive plate. The microlens array includes a plurality of power lines for individually addressing each of the microlenses of the microlens array.