Multi-Beam Inspection System Interlaced Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inspection systems are inadequate for detecting defects of different types and sizes on samples, as they often require specific inspection conditions that may not be universally applicable.
Innovation Solution
An inspection system with an illumination module that scans samples using multiple beams with varying optical properties and a mechanical stage that moves at different speeds in interlaced and non-interlaced modes, allowing for independent processing of detection signals from overlapping and non-overlapping scan lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single inspection condition is used, then the inspection system is simple to operate, but it cannot detect defects of different types effectively
Solution Approach 1:
The inspection system divides the sample into multiple regions and uses multiple beams with different optical properties to inspect different regions. Each beam is configured with specific optical characteristics suitable for detecting particular defect types, allowing the system to handle diverse defects without requiring complete system redesign.
Solution Approach 2:
The system employs a single illumination module capable of generating multiple beams with varying optical properties (wavelength, polarization, numerical aperture). This multi-functional capability allows one inspection system to detect multiple defect types across different sample regions, replacing what would traditionally require multiple specialized inspection systems.
2Productivity
If the mechanical stage moves at high speed, then productivity increases, but scan line overlap decreases affecting measurement precision
Solution Approach 1:
The system dynamically adjusts the mechanical stage speed based on the operating mode. In interlaced mode, higher speeds are used with coordinated beam scanning to maintain overlap, while in non-interlaced mode, speeds are optimized for throughput. This dynamic adaptation allows the system to maintain precision across varying productivity requirements.
Solution Approach 2:
The illumination module performs multiple scan iterations with periodic scanning patterns. During each iteration, beams scan specific regions, and the mechanical stage moves the sample in coordinated steps. This periodic scanning approach ensures comprehensive coverage and maintains scan line overlap necessary for precise defect detection even at high speeds.
3Adaptability or versatility
If multiple beams with different optical properties are used, then defect detection versatility improves, but device complexity increases
Solution Approach 1:
The system merges multiple beam generation capabilities into a single illumination module. By integrating multiple light sources or a tunable source with beam shaping optics, the system generates multiple beams with different optical properties (wavelengths, polarizations, numerical apertures) from one compact unit, reducing overall system complexity compared to using separate inspection systems for each beam type.
Data Source
AI summary
An inspection system that may include an illumination module that may be configured to scan a sample during multiple scan iterations; wherein during each scan iteration the illumination module scans each beam of a plurality of spaced apart beams along a scan line; a mechanical stage that may be configured to move the sample during the multiple scan iterations; a detection module; and a processor; wherein when the inspection system operates in an interlaced mode, the mechanical stage may be configured to move at a first speed thereby preventing a substantial overlap between scan lines obtained during the multiple scan iterations; wherein when the inspection system operates in a non-interlaced mode: the mechanical stage may be configured to move at a second speed that differs from the first speed thereby introducing an overlap between scan lines of different beams that may be obtained during different scan iterations; the detection module may be configured to generate detection signals in response to a detection of radiation emitted from the sample as a result of each scan line; and wherein the processor may be configured to independently process detection signals relating to different scan lines.