Substrate Imaging Using Absorption Wavelengths for Accurate Inspection
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Solution Overview
Problem
Existing substrate inspection methods fail to accurately capture image data that represents the state of the substrate's upper surface, particularly for different types of substrates, leading to inadequate inspection results.
Innovation Solution
A substrate imaging device and method that utilizes an illuminator to emit illumination light of specific wavelengths, an imager to capture images, and a controller to acquire inspection image data corresponding to the substrate's absorption wavelength, enabling precise inspection based on the substrate type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If strip-shaped light is emitted and the substrate is moved to capture image data, then the upper surface of the substrate can be inspected, but the image data does not accurately represent the state of the upper surface for certain substrate types
Solution Approach 1:
The patent applies local quality by using illumination light with specific wavelengths that correspond to the absorption characteristics of different substrate types. By selecting appropriate wavelengths (e.g., blue light for silicon carbide substrates, red or green light for other substrates), the inspection system optimizes image data accuracy for each substrate type locally, rather than using a universal wavelength that would compromise accuracy across all substrate types.
2Measurement precision
If illumination light of a single wavelength is used, then inspection accuracy for a specific substrate type is improved, but the device cannot adapt to different substrate types
Solution Approach 1:
The patent implements dynamics by making the illumination wavelength selectable and changeable based on the substrate type being inspected. The inspection device can dynamically switch between different wavelength lights (blue, red, green) depending on the absorption characteristics of the specific substrate material, thereby maintaining high inspection accuracy across multiple substrate types without requiring multiple fixed-wavelength devices.
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
Enables appropriate inspection of substrate surfaces by accurately capturing image data that corresponds to the substrate's absorption characteristics, improving the accuracy and reliability of defect detection and film thickness evaluation.
Implementation Method 1
the inspection image data corresponds to light having an absorption wavelength of the substrate
Data Source
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AI summary
A substrate imaging device includes an illuminator, an imager and a controller. The illuminator irradiates an upper surface of a substrate held by a substrate holding device with illumination light. The imager captures an image of the upper surface of the substrate irradiated with the illumination light. Based on an output of the imager, inspection image data representing a state of at least a partial area of the upper surface of the substrate is acquired. The inspection image data corresponds to light having a wavelength, with the light being absorbed by the substrate.