Charged Particle Beam Image Adjustment for Defect Detection
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Solution Overview
Problem
Charged particle beam devices face challenges in setting appropriate device conditions for defect pattern detection, especially when the defective pattern is not within the visual field, as existing methods do not provide a method for independent adjustment of device conditions.
Innovation Solution
A method is proposed that adjusts the contrast and brightness of images obtained by scanning a sample with a charged particle beam by adjusting the signal processing device to meet predetermined conditions, using multiple beam conditions and evaluating characteristics of images under different scanning conditions to optimize image processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If device conditions are adjusted based on visual field patterns, then detection accuracy improves, but the method becomes inapplicable when defective patterns are not in the visual field
Solution Approach 1:
The patent applies preliminary action by performing device condition adjustment using normal patterns before actual defective pattern detection. The system acquires images under multiple beam conditions, evaluates characteristics of normal patterns, and sets optimal device conditions in advance, enabling subsequent detection to work effectively even when defective patterns are not initially visible in the visual field.
2Adaptability or versatility
If multiple beam conditions are used for adjustment, then device condition setting becomes independent of sample state, but the adjustment process complexity increases
Solution Approach 1:
The patent applies parameter changes by varying beam conditions (such as beam current, scanning speed, or focus) to acquire multiple images under different parameters. By evaluating characteristics across these parameter variations and selecting optimal settings, the system achieves independent device condition setting without requiring complex manual adjustment procedures.
Solution Approach 2:
The system implements self-service through automated evaluation of image characteristics and automatic determination of optimal device conditions. The evaluation unit assesses image quality metrics and the control unit autonomously adjusts device parameters, eliminating the need for operator intervention and simplifying the overall adjustment process despite using multiple beam conditions.
3Illumination intensity
If device conditions are optimized for normal patterns, then image quality improves, but defective pattern detection sensitivity may be compromised
Solution Approach 1:
The patent applies partial or excessive action by acquiring images under multiple beam conditions beyond what would be used for a single optimization target. This excessive sampling of beam conditions ensures that at least one condition will be suitable for detecting defective patterns, even if the optimal condition for normal pattern visualization differs from that needed for defect detection.
Data Source
AI summary
The present disclosure hereinafter proposes a charged particle beam device and a method for adjusting a charged particle beam device which aim to appropriately set device conditions independently of a state of a sample. The present disclosure proposes a method and a system for adjusting contrast and brightness of an image, comprising: adjusting offset (step 112) of a signal processing device of the charged particle beam device so that the brightness of a pattern in an image obtained by scanning with a first charged particle beam (first intermittent condition beam) becomes a predetermined value; and adjusting a gain (step 114) of the signal processing device so that the brightness of a pattern in an image obtained by scanning with a second charged particle beam, which is a pulse beam (second intermittent condition beam) different from the first charged particle beam in at least one of irradiation time, irradiation distance, interval time between irradiation points, and distance between irradiation points, becomes a predetermined value.