Particle Beam Raster Pattern Variation for Artifact Reduction
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Solution Overview
Problem
Existing particle beam devices, such as SEM and TEM, produce images with artifacts due to minor periodic disturbances, which complicate the evaluation of FFT images, especially when imaging small structures like atomic structures.
Innovation Solution
A method and device that define a raster pattern with varying time intervals between raster points, allowing the particle beam to dwell at each point for different time periods, and optionally using different raster patterns like spiral or rectangular shapes, to minimize artifacts in the resulting images and FFT images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard raster process with fixed time intervals is used for particle beam scanning, then the imaging process is simple and efficient, but artifacts appear in the images due to periodic disturbances
Solution Approach 1:
The patent applies dynamics by varying the time intervals between raster points instead of using fixed intervals. The raster pattern includes raster points with different time intervals, where at least one time interval differs from others. This dynamic approach breaks the periodicity that causes artifacts in Fourier transform images, thereby improving image quality without requiring complex additional hardware.
2Measurement precision
If the particle beam dwells at each raster point for identical time periods, then the scanning process is straightforward, but artifacts become visible in FFT images due to correlation between time fluctuations and spatial position
Solution Approach 1:
The patent changes the time parameter by defining varying time intervals between different raster points. Specifically, the method defines a raster pattern where the time interval between adjacent raster points varies, with at least one interval being different from others. This parameter variation disrupts the correlation between temporal fluctuations and spatial positioning, reducing artifact visibility in FFT images while maintaining straightforward scanning control.
3Manufacturing precision
If a fixed raster pattern is used for scanning, then the imaging process is efficient and quick, but periodic disturbances create artifacts that complicate evaluation of small structures
Solution Approach 1:
The patent applies periodic action in reverse by intentionally introducing aperiodic variations in the raster scanning process. Instead of using uniform periodic scanning that creates artifacts, the method varies the time intervals between raster points in an aperiodic manner. This breaks the correlation between periodic disturbances and spatial patterns, improving representation accuracy for small structures while maintaining acceptable imaging speed.
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 approach significantly reduces the visibility of artifacts in FFT images, leading to clearer representations of objects, especially in high-resolution imaging of small structures, by breaking the correlation between time fluctuations and spatial position.
Implementation Method 1
The particles in the particle beam interact with the object to be examined. As a result of the interaction, interaction particles are emitted from the object to be examined and interaction radiation is generated.
Data Source
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AI summary
The invention relates to a method for producing a representation of an object by means of a particle beam. The invention also relates to a particle beam device for carrying out the method. The invention is based on the object of specifying the method and the particle beam device for producing a representation of an object such that images which are produced, in particular including FFT images, are as free as possible of artifacts which are not caused by the object to be examined. This is achieved in particular in that pixel lives, line flyback times and pixel pause times are varied in raster patterns.