3D Tomography Alignment Transfer Across Switched Imaging Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The generation of 3D tomographic data from nm-scale samples, particularly semiconductor samples, is challenged by lateral stage drifts, image distortions, and the need for compromising imaging conditions between fiducials and the structure of interest, leading to inefficiencies and systematic errors in alignment.
Innovation Solution
A method that transfers alignment information from a first set of images taken at one time with a specific imaging mode to a second set taken at different times with potentially different pixel sizes or sensors, using time-dependent interpolation to maintain accurate alignment and improve throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If imaging conditions are optimized for fiducials, then alignment precision is improved, but imaging quality of the structure of interest deteriorates
Solution Approach 1:
The patent divides the imaging process into two separate sets: a first set of images optimized for fiducial alignment and a second set optimized for structure imaging. By segmenting the imaging task into distinct phases with different optimization criteria, the system achieves both precise alignment and high-quality structure imaging without compromise.
Solution Approach 2:
The patent performs alignment imaging first (first set of images) before acquiring the final structure images (second set). The alignment information obtained in advance is then transferred to guide the second imaging set, allowing the structure images to be acquired under optimal conditions for that purpose without being constrained by fiducial imaging requirements.
2Productivity
If imaging is performed in a single mode, then process simplicity is maintained, but imaging efficiency and flexibility deteriorate
Solution Approach 1:
The patent implements a dynamic imaging system that can switch between different imaging modes and parameters. The system adapts by using first imaging conditions for fiducial alignment and second imaging conditions for structure capture, allowing optimal performance for each imaging objective while maintaining overall process efficiency.
Solution Approach 2:
The patent changes imaging parameters (such as pixel size, acceleration voltage, or scanning settings) between the first and second image sets. By adjusting these parameters according to the specific imaging objective, the system achieves both alignment precision and structure imaging quality without requiring a single compromised configuration.
3Measurement precision
If alignment information is not transferred between image sets, then process complexity is reduced, but alignment accuracy and 3D reconstruction quality deteriorate
Solution Approach 1:
The patent copies alignment information (such as fiducial positions and transformation matrices) from the first image set to guide the acquisition and processing of the second image set. This copying of alignment data ensures consistent spatial reference across different imaging modes while maintaining a relatively simple implementation approach.
Solution Approach 2:
The patent uses alignment information as an intermediary element that connects the first and second image sets. This intermediary data structure (containing fiducial positions and transformation parameters) enables accurate alignment between images taken under different conditions without requiring complex real-time coordination between imaging modes.
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 enhances the precision and speed of 3D data generation by allowing for different imaging conditions and reducing systematic errors, enabling more efficient alignment and improved 3D tomography data quality.
Implementation Method 1
a focused ion beam (FIB) of Ga ions is used to cut off layers at an edge of a sample slice by slice ('milling')
Implementation Method 2
a SEM or HIM (not shown) is used for scanning imaging the front surface of the cross-section 11
Data Source
AI summary
The present disclosure provides a method of transferring alignment information from a first set of images to a second set of images, a respective computer program product and a respective inspection device. A first set of cross-section images in a first imaging mode is obtained, the first cross-section images being taken at times Tai. A second set of cross-section images in a second imaging mode is obtained, the second cross-section images being taken at times Tbj, the times Tbj differing from the times Tai. Obtaining the first and second sets of cross-section images comprises subsequently removing a cross-section surface layer of a sample to make a new cross-section accessible for imaging, and imaging the new cross-section of the sample in the first imaging mode or in the second imaging mode. Switching is performed between the first and second imaging modes while obtaining the first and second sets of cross-section images.