Electron Beam Tilting with Dispersion Compensation
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Solution Overview
Problem
High electron beam intensity in electron beam devices leads to increased electron-electron interactions, reducing energy and spatial resolution, and electronic tilting of the beam introduces chromatic aberrations, degrading image quality.
Innovation Solution
An electron beam device with a beam tilting arrangement that adjusts the primary electron beam to an oblique angle using deflectors and a dispersion compensation element to compensate for chromatic aberrations, minimizing beam widening and maintaining high resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high electron beam intensity is used, then throughput is improved, but electron-electron interactions increase causing reduced energy and spatial resolution
Solution Approach 1:
The patent divides the electron beam into multiple separate beams using a beam splitter, reducing the intensity of individual beams and thereby minimizing electron-electron interactions while maintaining overall throughput through parallel processing of multiple beams
Solution Approach 2:
The patent introduces an intermediary optical system with multiple beam paths that separates and redistributes the electron beam, allowing high total intensity to be achieved through parallel lower-intensity beams rather than a single high-intensity beam
2Adaptability or versatility
If electronic tilting of the beam is used, then additional image information is obtained, but chromatic aberrations increase reducing image quality
Solution Approach 1:
The patent applies dispersion compensation before the electron beam reaches the specimen, pre-correcting chromatic aberrations that would otherwise be introduced by beam tilting, thereby maintaining image quality while enabling multi-angle imaging
Solution Approach 2:
The patent changes the dispersion parameters of the optical system to compensate for chromatic aberrations, adjusting the beam path parameters to maintain focus and image quality across different tilting angles
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 solution allows for high-intensity electron beam operation with reduced chromatic aberrations, enhancing throughput and image quality by compensating for beam aberrations and minimizing electron-electron interactions.
Implementation Method 1
a beam separator having a first dispersion for separating a signal electron beam from the primary electron beam
Implementation Method 2
a dispersion compensation element adapted for adjusting a compensation dispersion of the primary electron beam such as to compensate for a beam aberration resulting from the first dispersion and from the chromatic aberration
Implementation Method 3
an objective electron lens for focusing the primary electron beam onto a specimen
Implementation Method 4
a beam emitter for emitting a primary electron beam
Data Source
AI summary
An electron beam device 100 includes: a beam emitter 102 for emitting a primary electron beam 101; an objective electron lens 127 for focusing the primary electron beam 101 onto a specimen 130, the objective lens defining an optical axis 126; a beam tilting arrangement 103 configured to direct the primary electron beam 101 to the electron lens 127 at an adjustable offset from the optical axis 126 such that the objective electron lens 127 directs the electron beam 101 to strike the specimen 130 at an adjustable oblique beam landing angle, whereby a chromatic aberration is caused; a beam separator 115 having a first dispersion for separating a signal electron beam 135 from the primary electron beam 101; and a dispersion compensation element 104 adapted to adjust a compensation dispersion of the primary electron beam 101 so as to compensate for a beam aberration resulting from the first dispersion and from the chromatic aberration.