Electron Microscope Dynamic Probe Adjustment for Crystallinity Analysis
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Solution Overview
Problem
Current electron microscopes face challenges in efficiently and accurately analyzing crystallinity in minute areas, particularly in semiconductor device development, as they struggle to provide precise crystal orientation analysis and overlook areas with crystallinity due to varying detection intensities of Kikuchi lines based on incident directions and angles.
Innovation Solution
An electron microscope equipped with an electron beam irradiation unit, a subject holding unit capable of rotation and inclination, and detection units for secondary electrons and electron backscatter diffraction patterns, along with a control analysis unit that calculates the mean angular deviation (MAD) value to assess crystal similarity and adjust the incident direction and angle for optimal analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electron backscatter diffraction pattern detection is performed with fixed incident direction and angle, then the analysis process is simple, but crystallinity analysis accuracy deteriorates due to varying detection intensities of Kikuchi lines
Solution Approach 1:
The patent implements dynamic adjustment of the electron probe's incident direction and angle by rotating and inclining the subject holding unit. The control analysis unit automatically adjusts these parameters based on detected crystallinity characteristics, transforming the fixed observation mode into a dynamic adaptive observation mode to optimize detection accuracy for different crystal regions.
Solution Approach 2:
The patent changes the physical parameters of electron beam incidence (direction and angle) based on the detected crystallinity state. By adjusting these parameters dynamically, the system adapts to varying Kikuchi line detection intensities and maintains high measurement precision across different crystal orientations and grain structures.
2Productivity
If the electron probe irradiates all areas uniformly, then the coverage is complete, but the analysis efficiency deteriorates due to processing unnecessary amorphous regions
Solution Approach 1:
The patent applies local quality by differentiating between crystalline and amorphous regions through MAD value calculation. The system identifies areas with crystallinity characteristics (low MAD values) and focuses detailed analysis only on these regions, while treating amorphous regions differently, thereby optimizing resource allocation and improving overall analysis efficiency without sacrificing detection reliability.
Solution Approach 2:
The patent segments the analysis process into two stages: initial uniform scanning to identify crystalline regions based on MAD values, followed by focused detailed analysis only in those identified regions. This segmentation strategy eliminates unnecessary processing of amorphous areas while ensuring complete coverage of crystalline regions, thus improving productivity without compromising measurement precision.
3Measurement precision
If multiple rotation and inclination adjustments are performed to find optimal viewing angles, then the detection accuracy improves, but the analysis time increases
Solution Approach 1:
The patent implements feedback control where the control analysis unit continuously monitors MAD values and crystallinity detection results during rotation and inclination adjustments. Based on this feedback, the system intelligently determines when optimal viewing angles have been achieved and stops further adjustments, preventing unnecessary time consumption while ensuring detection accuracy is maximized.
Solution Approach 2:
The patent performs preliminary scanning with initial rotation and inclination settings to identify regions of interest and estimate optimal viewing angles before conducting detailed analysis. This preliminary action reduces the number of adjustments needed during subsequent detailed examination, thereby balancing detection accuracy with time 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
Enables efficient and accurate crystallinity analysis by identifying suitable areas for evaluation, preventing the overlooking of crystalline regions and improving analysis accuracy by adjusting the electron probe's direction and angle, thus enhancing the evaluation of grain size and orientation in semiconductor devices.
Implementation Method 1
an electron beam irradiation unit that irradiates an irradiation area of a surface of a subject with an electron beam
Implementation Method 2
a first detection unit that detects secondary electrons emitted from the subject by irradiation with the electron beam
Implementation Method 3
a second detection unit that detects an electron backscatter diffraction pattern generated from the subject by irradiation with the electron beam
Data Source
AI summary
An electron microscope includes an electron beam irradiation unit, a subject holding unit that has a subject installation surface, and a second detection unit that detects an EBSD image. In addition, the electron microscope includes an SEM control unit that controls an operation of the subject holding unit, and an EBSD analysis unit that analyzes a crystal structure of a subject based on the EBSD image. The subject holding unit is rotatable around an axis parallel to a direction of irradiation with an electron beam, and is configured such that the subject installation surface is inclinable with respect to a plane perpendicular to the direction of irradiation with the electron beam. The EBSD analysis unit has an MAD value calculation unit that calculates a degree of similarity between the EBSD image and a reflector, and the SEM control unit controls a rotation operation or an inclination operation of the subject holding unit based on the degree of similarity.