Stacked Metasurface Image Sensor for Integrated Optical Functions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors face limitations in improving certain aspects, such as optical function complexity and integration with semiconductor substrates, which affect image quality and manufacturing simplicity.
Innovation Solution
The integration of stacked bidimensional metasurfaces with sub-wavelength pads, each serving distinct optical functions like polarization routing and focusing, directly on the semiconductor substrate at a short distance from the illumination surface, simplifies design and manufacturing while enhancing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple optical elements (focusing elements, wavelength filtering elements, polarization filtering elements) are placed in front of photodetectors, then optical functions are improved, but device complexity increases
Solution Approach 1:
The patent combines multiple optical elements (focusing lens, wavelength filter, polarization filter) into a single integrated optical element formed directly on the semiconductor substrate. This merging approach maintains all necessary optical functions while eliminating the complexity of stacking multiple separate elements, directly resolving the contradiction between functional versatility and system complexity.
Solution Approach 2:
The integrated optical element performs multiple functions simultaneously: it acts as a focusing lens, a wavelength filter, and a polarization filter all in one component. This multi-functionality allows the system to achieve the same optical performance as multiple separate elements would provide, but with reduced structural complexity.
2Reliability
If optical elements are placed far from the semiconductor substrate, then optical performance is improved, but manufacturing complexity and assembly difficulty increase
Solution Approach 1:
The optical element is merged with the semiconductor substrate by forming it directly on the substrate surface. This integration eliminates the need for separate mounting and positioning of optical elements, thereby simplifying manufacturing and assembly while maintaining the required optical performance through optimized design.
Solution Approach 2:
The optical element is formed during the semiconductor manufacturing process itself, before final assembly. This preliminary formation of the optical element on the substrate eliminates subsequent assembly steps and ensures precise alignment, thereby improving ease of manufacture without compromising optical performance.
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 improves image quality and simplifies sensor assembly by breaking down complex optical functions into manageable components, compatible with microelectronics manufacturing constraints, and reduces the complexity of optical systems.
Implementation Method 1
the first optical function is a function of routing of the incident light according to its polarization state
Implementation Method 2
the second optical function is a function of focusing of light towards the photodetectors of the underlying pixels
Implementation Method 3
Each pixel comprises a photodetector, for example, a photodiode, formed in the semiconductor substrate
Data Source
AI summary
The present description concerns an image sensor formed inside and on top of a semiconductor substrate, the sensor comprising a plurality of pixels, each comprising a photodetector formed in the substrate, the sensor comprising at least first and second bidimensional metasurfaces stacked, in this order, in front of said plurality of pixels, each metasurface being formed of a bidimensional array of pads, the first metasurface having a first optical function and the second metasurface having a second optical function different from the first optical function.