Electron Beam Inspection Overlap Correction for Defect Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electron beam inspection apparatuses face reduced defect detection capability due to image changes caused by pattern electrification, particularly in regions repeatedly irradiated with electron beams, leading to potential false defect determination.
Innovation Solution
An electron beam inspection apparatus and method that includes a stage holding a substrate with a pattern, an electron beam column irradiating multiple beams with overlapping regions, image storage units for capturing inspection images, a correction coefficient storage unit, and an image correction unit that adjusts the brightness of overlap regions using correction coefficients to prevent image changes from electrification, allowing for accurate defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple electron beams are used to irradiate adjacent regions to improve inspection throughput, then productivity increases, but image changes occur in overlap portions due to electrification
Solution Approach 1:
The patent applies preliminary action by calculating and storing correction coefficients before the actual inspection process. These coefficients are derived from predetermined electron beam irradiation conditions and are used to pre-correct images in overlap portions, preventing electrification effects from compromising defect detection accuracy during high-speed multi-beam inspection
2Productivity
If electron beams are repeatedly irradiated onto the same region to improve inspection efficiency, then productivity increases, but the pattern becomes electrified causing image changes
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different regions in the inspection image. Specifically, overlap portions that are subjected to repeated electron beam irradiation and thus affected by electrification are corrected using predetermined correction coefficients, while non-overlap portions are processed normally. This localized correction approach maintains measurement precision in critical areas without compromising overall inspection 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
The solution effectively corrects image changes in overlap regions, enhancing the defect detection capability of electron beam inspection apparatuses by ensuring accurate comparison and reducing false defect determinations.
Implementation Method 1
emits electron beams onto a wafer, detects secondary electrons emitted from a pattern on the wafer
Implementation Method 2
detects secondary electrons emitted from a pattern on the wafer or electrons reflected from the wafer
Data Source
AI summary
An electron beam inspection apparatus according to an embodiment includes a stage holding a substrate with a pattern; an electron beam column irradiating the substrate with multiple beams including a plurality of electron beams such that adjacent regions irradiated with the electron beams have an overlap portion therebetween; a first image storage unit storing a first inspection image acquired by irradiating a first inspection region of the substrate with the multiple beams; a second image storage unit storing a second inspection image acquired by irradiating a second inspection region of the substrate with the multiple beams; a correction coefficient storage unit storing a correction coefficient for correcting an image of the overlap portion; an image correction unit correcting an image of the overlap portion using the correction coefficient; and a comparison unit comparing the first inspection image with the second inspection image.