Multi-Beam Inspection Detector with Oversized Elements
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Solution Overview
Problem
Existing inspection apparatuses using multiple electron beams for semiconductor device manufacturing suffer from reduced inspection accuracy due to beam blur and movement issues, causing beams to fall outside the detector's light-receiving area.
Innovation Solution
The inspection apparatus employs a detector with detecting elements larger than the beam blur size to accurately image and detect multiple electron beams, and uses a Wien filter and deflector to ensure precise beam positioning and separation, allowing for effective pattern defect inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple electron beams are used for inspection, then inspection throughput is improved, but beam blur and movement cause beams to fall outside the detector's light-receiving area, reducing inspection accuracy
Solution Approach 1:
The patent implements dynamic beam control by making the electron beams movable along with the stage movement. The beams are dynamically adjusted to track and follow the stage position, ensuring continuous accurate detection of pattern defects during sample scanning without losing beam-signal alignment
Solution Approach 2:
The patent changes the light-receiving area parameter of the detector by making it larger than the beam blur size. This parameter change ensures that even when beams experience blur or movement, they remain within the detector's detection range, maintaining inspection accuracy while using multiple beams for high throughput
2Measurement precision
If the detector's light-receiving area is made larger to cover beam blur, then inspection accuracy is improved, but detector size and complexity increase
Solution Approach 1:
The patent dynamically adjusts the beam positions to follow stage movement, which allows the use of a moderately sized detector. The dynamic tracking capability compensates for stage motion, reducing the need for an excessively large detector area while maintaining accurate detection throughout the scanning process
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 configuration enhances inspection accuracy by ensuring that all beam signals are detected correctly, even during stage movement, thereby improving the overall yield of semiconductor device manufacturing.
Implementation Method 1
a Wien filter separating charged particle beams from the incident electron beams
Implementation Method 2
a detector on which a plurality of charged particle beams of charged particles released from the inspection target substrate are imaged, the detector detecting each of the charged particle beams as an electrical signal
Data Source
AI summary
An inspection apparatus according to an embodiment includes an irradiation part configured to irradiate an inspection target substrate with multiple beams including energy beams, a detector, on which a plurality of charged particle beams of charged particles released from the inspection target substrate are imaged, configured to detect each of the charged particle beams as an electrical signal, and a comparing unit configured to compare reference image data and image data that is reproduced based on the detected electrical signals and that represents patterns formed on the inspection target substrate to inspect the patterns. The detector includes a plurality of detecting elements corresponding one-to-one to the charged particle beams. The detecting elements each have a size greater than a size that covers a beam blur of each charged particle beam imaged on the detector.