Dynamic Spatial Filter for High-Accuracy Contamination Inspection
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Solution Overview
Problem
Existing contamination inspection devices face challenges in achieving high accuracy due to the limitations of liquid crystal filters and mechanical spatial filters, which result in incomplete light shading and distortion, especially when dealing with patterns of varying intervals and lens aberrations, leading to reduced detection accuracy and increased costs.
Innovation Solution
A contamination inspection device equipped with a spatial filter that includes light shading materials and a control member capable of adjusting shape, angle, and interval, utilizing piezoelectric elements, elastic materials, or motors to dynamically control the light shading patterns, allowing for precise shading of diffracted lights on the Fourier transformation surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If liquid crystal filters are used to form light shading patterns, then the pattern diversity is improved, but the light shading completeness deteriorates due to incomplete shading ability
Solution Approach 1:
The spatial filter is divided into multiple independently controllable light shading materials (first, second, third light shading materials) that can be separately adjusted. This segmentation allows each material to be precisely controlled to achieve complete shading while maintaining pattern diversity through independent positioning and orientation adjustments.
2Stability of the object's composition
If mechanical spatial filters with equal interval coil springs are used, then the arrangement regularity is improved, but the adaptability to varying pitch diffracted lights deteriorates
Solution Approach 1:
The spatial filter transitions from a static equal-interval mechanical structure to a dynamic configuration where light shading materials can be independently positioned at different intervals. The control members enable real-time adjustment of positions and orientations, allowing the system to adapt to varying pitch diffracted lights while maintaining stable shading performance.
Solution Approach 2:
Different regions of the spatial filter are assigned different interval characteristics. The first, second, and third light shading materials are positioned at different intervals corresponding to different pitch requirements, allowing local optimization for various diffracted light patterns rather than using a uniform structure.
3Adaptability or versatility
If multiple spatial filters are prepared to correspond to various light shading patterns, then the adaptability is improved, but the device complexity and cost increase
Solution Approach 1:
A single spatial filter unit is designed to perform multiple functions by incorporating control members that can independently adjust the position and orientation of different light shading materials. This universal design replaces the need for multiple dedicated spatial filters, reducing device complexity while maintaining the ability to handle various light shading patterns.
Solution Approach 2:
The spatial filter incorporates dynamic control capabilities through control members that can adjust light shading material positions and orientations in real-time. This dynamic adaptability allows one filter to replace multiple static filters, each designed for specific patterns, thereby reducing the overall number of filters needed while maintaining comprehensive pattern coverage.
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 solution enables high-accuracy contamination inspection by providing customizable light shading patterns, improving detection accuracy, and reducing the need for multiple spatial filters, thus lowering costs and device size.
Implementation Method 1
utilizing piezoelectric elements, elastic materials, or motors to dynamically control the light shading patterns
Implementation Method 2
utilizing piezoelectric elements, elastic materials, or motors to dynamically control the light shading patterns
Implementation Method 3
utilizing piezoelectric elements, elastic materials, or motors to dynamically control the light shading patterns
Implementation Method 4
a spatial filter for shading the diffracted lights from the inspection target substrate
Data Source
AI summary
Provided are a contamination inspection method and a contamination inspection device for highly accurately detecting a defect in a wafer, a liquid crystal substrate and media or the like including patterns, for example, a semiconductor device or the like. The first aspect of the present invention is a contamination inspection device comprising: an irradiation optical system for irradiating lights on the inspection target substrate; and a spatial filter for shading diffracted lights form the inspection target substrate. Herein, the spatial filter comprises: a plurality of light shading materials; a control member for changing at least one of parameters selected from a shape, an angle and an interval with respect to the light shading material, and a control unit for controlling the control members.