Light Scattering Inspection System Detector Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current light scattering inspection systems for semiconductor manufacturing require time-consuming and error-prone experimental measurements to determine optimal detector configurations, which are unsuitable for real-time optimization in fabrication environments, leading to prolonged development cycles and reduced accuracy.
Innovation Solution
A computer-implemented method and system that determine a three-dimensional map of signal-to-noise ratio values across a scattering hemisphere to optimize the configuration of a detection subsystem without physical measurements, using metrology data and simulation engines to position detectors and adjust aperture and polarizing filters for enhanced sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If experimental measurements are used to determine optimal detector configurations, then measurement accuracy can be improved, but time consumption and error rates increase
Solution Approach 1:
The patent uses simulation to create a virtual model of the inspection system and specimen, replacing physical experimental measurements with computational experiments. The simulation engine replicates the optical paths, light scattering behaviors, and detector responses to determine optimal configurations without requiring actual hardware measurements, thereby eliminating time-consuming setup and measurement errors while maintaining accuracy.
Solution Approach 2:
The patent replaces the mechanical/physical measurement system with a computer-based simulation system. Instead of physically positioning detectors and measuring light scattering in the lab, the system uses computational models to calculate optimal detector configurations, substituting physical experimentation with algorithmic optimization.
2Measurement precision
If spot size is reduced to increase defect signal-to-noise ratio, then sensitivity is improved, but throughput decreases
Solution Approach 1:
The patent employs adaptive optimization where the simulation engine dynamically adjusts detector configuration parameters based on the specific specimen characteristics and defect types being inspected. Rather than using a fixed spot size or detector arrangement, the system calculates optimal configurations that balance sensitivity and throughput requirements for each inspection scenario.
Solution Approach 2:
The patent optimizes multiple parameters simultaneously including detector positions, aperture sizes, and polarizing filter orientations to achieve the best compromise between sensitivity and throughput. By changing these parameters based on simulation results rather than relying on fixed physical configurations, the system can adapt to different inspection requirements.
3Measurement precision
If aperture is modified to block scattered light from surface, then defect signal-to-noise ratio increases, but system complexity increases
Solution Approach 1:
The patent uses simulation to model and optimize aperture configurations without requiring physical trial-and-error modifications to the optical system. The simulation engine calculates the optimal aperture geometry and positioning to maximize defect signal-to-noise ratio, then this virtual design is implemented in the actual system, avoiding complex iterative physical adjustments.
4Measurement precision
If laser power is increased to enhance defect scattering signal, then sensitivity improves, but energy consumption increases
Solution Approach 1:
The patent optimizes the laser power parameter as part of the overall detector configuration optimization process. The simulation engine determines the minimum laser power required to achieve the desired sensitivity level, avoiding excessive power consumption while maintaining adequate defect detection capability.
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 enables real-time optimization of detection subsystems, reducing error and development time, and improving defect detection sensitivity by up to 34% for smaller defect sizes, allowing for more accurate and efficient semiconductor wafer inspection.
Implementation Method 1
light scattering inspection systems for semiconductor manufacturing
Implementation Method 2
background noise arising from diffuse reflectance of the laser spot on that surface
Data Source
AI summary
Computer-implemented methods and systems for determining a configuration for a light scattering inspection system are provided. One computer-implemented method includes determining a three-dimensional map of signal-to-noise ratio values for data that would be acquired for a specimen and a potential defect on the specimen by the light scattering inspection system across a scattering hemisphere of the inspection system. The method also includes determining one or more portions of the scattering hemisphere in which the signal-to-noise ratio values are higher than in other portions of the scattering hemisphere based on the three-dimensional map. In addition, the method includes determining a configuration for a detection subsystem of the inspection system based on the one or more portions of the scattering hemisphere.