Shared-Microlens Image Sensor Layout for High-Density Pixel Sharing
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Solution Overview
Problem
Current image sensors face challenges in increasing integration density and improving performance due to limitations in pixel sharing structures and transistor configurations.
Innovation Solution
The image sensor design incorporates a substrate with specific region arrangements, overlapping microlenses, and multiple photoelectric conversion elements, along with various pixel transistors to enhance signal processing and integration density, including multiple transfer gates and a floating diffusion region to manage signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a sharing structure with multiple pixels sharing one unit pixel is used, then integration density increases, but device complexity increases
Solution Approach 1:
Multiple pixels (first through fourth pixels) share common components including the same unit pixel structure, transfer gates, and readout circuitry. This merging approach increases integration density by reducing the number of independent pixel units while maintaining the functional capability of multiple photoelectric conversion elements.
Solution Approach 2:
The unit pixel structure and associated circuitry are designed to serve multiple pixels simultaneously. The transfer gates and readout circuitry perform universal functions across all shared pixels, reducing overall device complexity while achieving high integration density.
2Reliability
If multiple photoelectric conversion elements are used per pixel, then sensitivity improves, but device complexity increases
Solution Approach 1:
Multiple photoelectric conversion elements (first through fourth photoelectric conversion elements) are combined within a shared unit pixel structure. This merging approach improves sensitivity by accumulating signals from multiple elements while reducing device complexity through shared circuitry and common readout paths.
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 design improves the integration density and performance of image sensors by enabling efficient signal processing and noise resistance through the use of shared microlenses and multiple pixel transistors, leading to enhanced read performance and sensitivity.
Implementation Method 1
a first photoelectric conversion element disposed in a first pixel region of the first region and a second photoelectric conversion element disposed in a second pixel region of the second region
Data Source
AI summary
Image sensors are provided. The image sensors may include a substrate including first, second, third and fourth regions, a first photoelectric conversion element in the first region, a second photoelectric conversion element in the second region, a third photoelectric conversion element in the third region, a fourth photoelectric conversion element in the fourth region, a first microlens at least partially overlapping both the first and second photoelectric conversion elements, and a second microlens at least partially overlapping both the third and fourth photoelectric conversion elements. The image sensors may also include a floating diffusion region and first, second and third pixel transistors configured to perform different functions from each other. Each of the first, second and third pixel transistors may be disposed in at least one of first, second, third and fourth pixel regions. The first pixel transistor may include multiple first pixel transistors.