Multi-Beam Charged-Particle Optics for Macro-Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charged particle inspection apparatuses face challenges in improving throughput and correcting macro-aberrations in multi-beam inspection systems, which affect the efficiency and accuracy of defect detection in semiconductor manufacturing.
Innovation Solution
The apparatus incorporates a condenser lens array to separate a beam of charged particles into sub-beams, an objective lens array to project these sub-beams onto a sample, and a corrector array with elongate electrodes to apply a potential difference for deflection and aberration correction, enhancing the inspection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a multi-beam charged particle inspection system is used to improve throughput, then productivity increases, but macro-aberrations in the beam paths cause degradation in measurement precision
Solution Approach 1:
The patent applies local quality by providing individual aberration correction for each sub-beam path. Each sub-beam has its own corrector (electrostatic or magnetic) that can be independently adjusted to correct local macro-aberrations specific to that beam path, allowing each beam to maintain high precision while contributing to overall high throughput multi-beam inspection
Solution Approach 2:
The patent employs a universal correction approach where a single corrector element (electrostatic or magnetic field generator) can correct macro-aberrations for multiple sub-beams simultaneously. This multi-functional corrector design allows one component to serve multiple correction purposes across different beam paths, improving efficiency while maintaining precision
2Productivity
If the beam is separated into multiple sub-beams to increase inspection speed, then productivity improves, but the complexity of the optical system increases
Solution Approach 1:
The patent segments the single inspection task into multiple parallel sub-beam operations. By dividing the primary beam into multiple sub-beams that can simultaneously inspect different regions or the same region with different parameters, the system achieves higher throughput while managing complexity through modular beam path design
Solution Approach 2:
The patent combines multiple correction functions (electrostatic and magnetic field corrections) into a unified correction system that handles macro-aberrations for all sub-beams. This merging of correction mechanisms reduces overall system complexity by providing integrated control rather than separate correction systems for each beam
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 configuration improves the throughput and accuracy of defect detection by correcting macro-aberrations, allowing for higher-speed and more precise inspection of semiconductor substrates, thereby increasing yield and reducing the need for operator intervention.
Implementation Method 1
a condenser lens array configured to separate a beam of charged particles into a first plurality of sub-beams along a respective beam path and to focus each of the sub-beams to a respective intermediate focus
Implementation Method 2
an array of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample
Implementation Method 3
a corrector comprising an array of elongate electrodes, the elongate electrodes extending substantially perpendicular to the beam paths of the first plurality of sub-beams and arranged such that a second plurality of the sub-beams propagate between a pair of the elongate electrodes
Implementation Method 4
an electric power supply configured to apply a potential difference between the pair of elongate electrodes so as to deflect the second plurality of sub-beams by a desired amount
Data Source
AI summary
A charged-particle tool including: a condenser lens array configured to separate a beam of charged particles into a first plurality of sub-beams along a respective beam path and to focus each of the sub-beams to a respective intermediate focus; an array of objective lenses, each objective lens configured to project one of the plurality of sub-beams onto a sample; a corrector including an array of elongate electrodes, the elongate electrodes extending substantially perpendicular to the beam paths of the first plurality of sub-beams and arranged such that a second plurality of the sub-beams propagate between a pair of the elongate electrodes, the second plurality of sub-beams being a subset of the first plurality of sub-beams; and an electric power supply configured to apply a potential difference between the pair of elongate electrodes so as to deflect the second plurality of sub-beams by a desired amount.