Charged Particle Beam Inspection Throughput via Region Segmentation
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Solution Overview
Problem
Conventional charged particle beam inspection systems face inefficiencies in throughput due to the need to scan both interested and uninterested regions, leading to slow inspection speeds and wasted time, especially when samples have large areas of uninterested regions.
Innovation Solution
The method involves calculating an alternative stage speed and imaging scan compensation offsets to allow the charged particle beam to tightly follow the sample stage motion, scanning only the sampling regions by adjusting the beam's motion according to the calculated offsets, thereby increasing inspection throughput without sacrificing resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the charged particle beam scans the entire sample including both sampling regions and skip regions, then the inspection coverage is complete, but the inspection throughput is reduced due to scanning unnecessary areas
Solution Approach 1:
The sample area is segmented into sampling regions (where defects need to be detected) and skip regions (where inspection is not needed). The inspection system selectively scans only the sampling regions by calculating compensation offsets that adjust the beam scanning positions to bypass skip regions, thereby improving throughput without compromising defect detection capability.
2Speed
If the stage moves faster to increase throughput, then the inspection speed improves, but the beam cannot accurately follow the stage motion and scan the sampling regions precisely
Solution Approach 1:
The system performs preliminary calculations to determine compensation offsets based on the known geometry of sampling and skip regions. These offsets are pre-computed and stored, allowing the beam scanning positions to be accurately adjusted in real-time as the stage moves at high speed, thereby maintaining scan accuracy without sacrificing throughput.
3Loss of time
If the beam scanning area is reduced to only sampling regions, then the inspection time decreases, but the system complexity increases due to the need for region identification and compensation calculations
Solution Approach 1:
The system uses a simplified digital representation (copy) of the sample layout with defined sampling and skip regions to guide the inspection process. This digital model allows the control system to calculate compensation offsets without requiring complex real-time analysis of the actual sample geometry, thereby reducing computational complexity while achieving selective region scanning.
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 significantly enhances the inspection throughput by optimizing the stage speed and beam motion to focus on sampling regions only, reducing the time required to complete defect inspections and improving the overall efficiency of the charged particle beam inspection process.
Implementation Method 1
The primary charged particle beam source portion includes a charged particle gun 10... The secondary charged particles 20 emanating from the sample 9 is detoured by the E×B charged particle detour device 17 to the detector 21
Implementation Method 2
The secondary charged particles 20 emanating from the sample 9 is detoured by the E×B charged particle detour device 17
Data Source
AI summary
A method, apparatus and computer readable medium for charged particle beam inspection of a sample comprising at least one sampling region and at least one skip region is disclosed. The method, apparatus and computer readable medium comprise receiving an imaging recipe which at least comprises information of the area of the sampling and skip regions; calculating a default stage speed according to the imaging recipe; calculating an alternative stage speed at least according to the default stage speed, the sampling region area information, and the skip region area information; calculating at least one imaging scan compensation offset at least according to the alternative stage speed; and inspecting the sample at the alternative stage speed while adjusting the motion of the charged particle beam according to the imaging scan compensation offsets, such that the charged particle beam tightly follows the motion of the stage and images only the sampling regions on the sample.