Multi-Beam Electron Optics for Landing Energy Control
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Solution Overview
Problem
Existing charged-particle assessment tools face challenges in improving throughput and controlling the landing energy of electrons incident on the sample in a convenient manner, which affects the efficiency and accuracy of defect detection in semiconductor manufacturing.
Innovation Solution
A multi-beam electron-optical system with a control lens array and objective lens array is employed to control the landing energy, demagnification, and beam opening angle of charged particles, utilizing a potential source system to apply relative potentials to the electrodes for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single electron beam is used for inspection, then the system is simple to operate, but the throughput is low
Solution Approach 1:
The single electron beam is segmented into multiple sub-beams that can simultaneously inspect different regions of the sample. This segmentation increases throughput while maintaining operational simplicity through automated beam control
Solution Approach 2:
The electron beam system is designed to perform multiple functions: it can operate as a single beam for detailed inspection or split into multiple sub-beams for high-throughput inspection, providing versatility in inspection modes
2Adaptability or versatility
If the landing energy is fixed, then the system is easier to control, but the adaptability to different inspection requirements is reduced
Solution Approach 1:
The landing energy is made dynamically adjustable through independent control of the objective lens voltage for each sub-beam, allowing real-time adaptation to different inspection requirements without fixed energy constraints
Solution Approach 2:
The system enables independent parameter changes for each sub-beam, specifically the landing energy via objective lens voltage control, allowing optimization of inspection parameters for different sample regions or defect types
3Productivity
If multiple sub-beams are used to increase throughput, then the inspection efficiency improves, but the control of beam parameters becomes more complex
Solution Approach 1:
The system implements automated control where the controller automatically manages the splitting, focusing, and parameter adjustment of multiple sub-beams, reducing manual intervention complexity while maintaining high inspection efficiency
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
Enhances the throughput and accuracy of defect detection by allowing flexible control of electron landing energy, demagnification, and beam opening angle, thereby improving the overall yield and efficiency of semiconductor manufacturing processes.
Implementation Method 1
a plurality of control lenses, each configured to control a parameter of a respective sub-beam
Implementation Method 2
a plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample
Implementation Method 3
a potential source system configured to apply relative potentials to the control electrodes and objective electrodes so that the charged particles are incident on the sample with a desired landing energy
Data Source
AI summary
A multi-beam electron-optical system for a charged-particle assessment tool, the system comprising: a plurality of control lenses, a plurality of objective lenses and a controller. The plurality of control lenses are configured to control a parameter of a respective sub-beam. The plurality of objective lenses are configured to project one of the plurality of charged-particle beams onto a sample. The controller controls the control lenses and the objective lenses so that the charged particles are incident on the sample with a desired landing energy, demagnification and/or beam opening angle.