Multi-Layer Microlens Structure for Inclined Light Collection
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Solution Overview
Problem
Existing biometric devices, such as fingerprint recognition systems under screens, face issues with inclined incident light causing aberrations due to larger incident angles, resulting in lower quality image signals from photoelectric conversion elements.
Innovation Solution
A semiconductor device design incorporating at least two light-condensing structures with different refractive indices and a light-transmitting layer between them, effectively reducing comatic aberrations by optimizing the refractive indices and configurations of the micro-lenses to improve image signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light-condensing structure is used, then the device structure is simple, but comatic aberrations occur with inclined incident light resulting in lower image signal quality
Solution Approach 1:
The patent divides the light-condensing structure into multiple layers (first light-condensing structure and second light-condensing structure) with different refractive indices. Each layer processes light at different stages, with the first layer receiving inclined incident light and the second layer further condensing the light. This segmentation allows each layer to be optimized for its specific function, reducing comatic aberrations while maintaining manageable device complexity.
Solution Approach 2:
The patent employs composite material structures by combining light-condensing structures made of materials with different refractive indices (first refractive index for the first light-condensing structure, second refractive index for the second light-condensing structure). This composite approach enables precise control over light propagation paths and reduces optical aberrations, thereby improving image signal quality without excessive complexity.
2Productivity
If light-condensing structures with high refractive index materials are used, then light condensing efficiency is improved, but manufacturing precision and material selection become more difficult
Solution Approach 1:
The patent optimizes the refractive index parameters of the light-condensing structures by establishing specific ranges (first refractive index between 1.5-2.5, second refractive index between 1.3-2.0) and relationships (first refractive index greater than second). These parameter specifications balance light condensing efficiency with manufacturing feasibility, allowing sufficient efficiency while providing clear manufacturing guidelines.
Solution Approach 2:
The patent applies different refractive index characteristics to different parts of the optical system. The first light-condensing structure uses material with a higher refractive index range for initial light capture and condensation, while the second light-condensing structure uses material with a lower refractive index for fine-tuning and final condensation. This local differentiation optimizes overall performance while simplifying material selection for each component.
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
The semiconductor device effectively reduces comatic aberrations even with inclined incident light angles greater than 50 degrees, enhancing the quality of image signals from photoelectric conversion elements.
Implementation Method 1
the refractive index of the lower light-condensing structure and the refractive index of the light-transmitting layer are different, so that the (comatic) aberrations may be effectively reduced
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a substrate having photoelectric conversion elements. The semiconductor device also includes a first light-shielding layer disposed on the substrate and having first apertures. The semiconductor device further includes a light-adjusting structure disposed on the first light-shielding layer. Moreover, the semiconductor device includes a second light-shielding layer disposed on the light-adjusting structure and having second apertures. The semiconductor device also includes first light-condensing structures covering the second apertures. The semiconductor device further includes a third light-shielding layer disposed on the first light-condensing structure and having third apertures. Furthermore, the semiconductor device includes second light-condensing structures covering the third apertures. The semiconductor device also includes a first light-transmitting layer disposed between the second light-shielding layer and the third light-shielding layer. The refractive index of each first light-condensing structure and the refractive index of the first light-transmitting layer are different.