Multi-Beam Particle Microscope Alignment Using Extra Detection Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multi-beam particle microscopes face challenges in accurately aligning secondary individual particle beams in real-time during inspection, particularly due to drift and sample properties like charging effects, which can lead to positional deviations and require complex and slow adjustments.
Innovation Solution
A method for operating a multi-beam particle microscope that involves irradiating an object with charged particle beams, collecting secondary beams, projecting them onto detection regions, and using additional detection channels not assigned to any region to detect positional deviations, allowing for real-time correction without the need for pixelated detection units or complex signal evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex adjustment mechanisms are used to correct positional deviations of secondary beams, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where additional detection channels continuously monitor the actual incidence positions of secondary beams and provide correction signals to adjust the particle optical beam path in real-time, automatically compensating for positional deviations without complex manual adjustment mechanisms
Solution Approach 2:
The patent replaces complex mechanical adjustment mechanisms with an electronic control system that uses electromagnetic fields in the particle optical unit to adjust beam positions, enabling faster and more precise control without mechanical complexity
2Measurement precision
If real-time correction of positional deviations is implemented, then measurement precision is improved, but loss of time increases due to additional detection and correction steps
Solution Approach 1:
The patent enables continuous real-time correction by continuously reading additional detection channels and continuously adjusting the particle optical beam path during the inspection process, eliminating the need to stop for corrections and actually reducing total inspection time
Solution Approach 2:
The patent performs preliminary detection of positional deviations using additional detection channels before final image generation, allowing correction to be prepared in advance and applied without interrupting the main inspection workflow
3Measurement precision
If pixelated detection units are used to detect positional deviations, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the detection unit universal by using additional detection channels that can serve dual purposes: detecting positional deviations and contributing to image formation, eliminating the need for separate dedicated alignment detection hardware
Solution Approach 2:
The patent enables the detection unit to self-correct by using its own additional channels to detect positional deviations and generate correction signals that are automatically applied to the particle optical beam path, making the system self-aligning without external intervention
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
Enables simple and universal fast positional correction of secondary beams, improving inspection accuracy and throughput by allowing real-time adjustment of the particle optical beam path, thereby enhancing resolution and reducing the complexity of detection unit design.
Implementation Method 1
irradiating an object with a plurality of charged first individual particle beams; collecting second individual particle beams which emerge from the object on account of the first individual particle beams
Implementation Method 2
a particle optical unit with a particle optical beam path, configured to image, in focused fashion, the second individual particle beams onto a detection plane
Data Source
AI summary
A method for operating a multi-beam particle microscope in an inspection mode of operation and an associated multi-beam particle microscope are disclosed, wherein a detection unit comprises an image generation detection region with fixedly assigned detection channels and an adjustment detection region with additional detection channels. The fixedly assigned detection channels and the additional detection channels are in the same detection plane. Based on signals obtained via the additional detection channels, it is possible to correct an incidence position of the secondary beams on the detection unit in real time, to be precise independently of the specific structure of the detection unit.