Pattern Inspection Image Correction with Density-Adaptive Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pattern defect inspection methods for ultrafine circuit patterns in semiconductor and LCD manufacturing face challenges in accurately detecting extra-fine defects due to image degradation from repeated corrections and difficulties in setting parameters for image alignment and correction processes.
Innovation Solution
An integrated approach combining 2D input/output predictive modeling and bicubic interpolation for image correction, automatically switching between methods based on pattern density, to minimize image degradation and reduce the number of setup parameters, using an image correction device and apparatus that generates corrected pattern images for defect inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If repeated execution of image corrections (alignment, expansion/shrink correction, swell correction, resize correction, noise averaging) is performed, then image quality is improved, but accumulated errors cause appreciable image degradation or corruption
Solution Approach 1:
The patent changes the fundamental parameter of correction approach from sequential iterative corrections to a single-step predictive modeling correction. By using 2D predictive modeling that simultaneously accounts for alignment, expansion/shrink, swell, and noise effects, the system achieves high precision without accumulated errors from repeated operations.
Solution Approach 2:
The patent performs preliminary action by establishing a predictive model before actual defect inspection. The model is trained on reference data and used to pre-correct images, thereby preparing corrected images in advance without requiring repeated iterative corrections during the inspection process.
2Manufacturing precision
If multiple correction processes with many parameters are implemented, then image correction capability is improved, but difficulties in setting appropriate values for a great number of parameters and setup of execution order arise
Solution Approach 1:
The patent merges multiple separate correction processes (alignment, expansion/shrink correction, swell correction, resize correction, noise averaging) into a single integrated predictive modeling step. By combining these corrections into one simultaneous operation using 2D predictive modeling, the system maintains high correction capability while eliminating the complexity of setting and ordering multiple parameters.
3Device complexity
If 2D linear predictive modeling is used for image correction, then number of setup parameters is reduced, but failure to establish intended accuracy of model parameters occurs for pattern images with extra-low densities due to deficiency of information within matrix
Solution Approach 1:
The patent applies dynamics by making the correction method adaptive based on pattern density. The system automatically switches between 2D predictive modeling (for normal densities) and alternative correction methods (for extra-low densities) based on real-time analysis of the input image characteristics, thereby maintaining accuracy across varying conditions.
Solution Approach 2:
The patent changes the correction approach parameter based on image density conditions. For pattern images with extra-low densities, the system transitions from 2D predictive modeling to alternative correction methods that better handle information-deficient matrices, thus maintaining model parameter accuracy across different density conditions.
4Measurement precision
If bicubic interpolation-based alignment in units of subpixels is performed, then subpixel alignment accuracy is improved, but image degradation occurs from repeated corrections
Solution Approach 1:
The patent performs preliminary alignment and correction actions using predictive modeling before the main inspection process. By pre-establishing the corrected image through predictive modeling trained on reference data, the system achieves subpixel alignment accuracy without requiring repeated iterative corrections that would cause degradation.
Data Source
AI summary
An image correction device for use in a pattern inspection apparatus is disclosed, which has automatic adaptability to variations in density of a pattern image of a workpiece being tested. The device is operable to identify a two-dimensional (2D) linear predictive model from the pattern image of interest and determine the amount of eccentricity of a centroid position of this model. This amount is then used to switch between a corrected pattern image due to the 2D linear prediction modeling and a corrected image that is interpolated by bicubic interpolation techniques. A pattern inspection method using the image correction technique is also disclosed.