Semiconductor Sensor Photo Gate Pairs Shared Floating Diffusion
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Solution Overview
Problem
Conventional depth sensors have limitations in increasing their light receiving area and sensitivity, which affects their accuracy and efficiency in distance measurement using the time of flight (TOF) method.
Innovation Solution
The design incorporates a semiconductor sensor with a plurality of photo gate pairs, shared floating diffusion regions, and micro-lenses to enhance light reception and transmission efficiency, including a specific arrangement of photo gates and transistors to improve charge collection and processing, thereby increasing the light receiving area and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the light receiving area is increased, then sensitivity is improved, but device complexity increases
Solution Approach 1:
The sensor array is divided into multiple photo gate pairs, with each pair independently detecting light. This segmentation allows the total light receiving area to be increased by adding more photo gate pairs without requiring a single large complex structure, thereby improving sensitivity while managing device complexity through modular design
Solution Approach 2:
Multiple photo gates within each pair share common floating diffusion regions and readout circuitry. This merging of signal processing components allows the light receiving area to be expanded across multiple photo gates while avoiding proportional increases in complexity, as shared components serve multiple detection elements
2Productivity
If photo gates are arranged in pairs with shared floating diffusion regions, then transmission efficiency of photo charges is improved, but capacitance increases
Solution Approach 1:
Photo gates within each pair share common floating diffusion regions, allowing multiple photo gates to transmit charges to the same collection node. This merging reduces the total number of separate readout paths and associated capacitance, while maintaining high transmission efficiency through dedicated transmission transistors for each photo gate pair
3Use of energy by moving object
If micro-lenses are added to each photo gate pair, then light reception is improved, but device complexity increases
Solution Approach 1:
Micro-lenses are added locally to each photo gate pair to focus incoming light precisely onto the active detection area. This local enhancement improves light reception efficiency without requiring system-wide complex optical systems, as each micro-lens is a simple localized component that enhances the specific photo gate pair beneath it
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 results in improved accuracy and sensitivity of depth measurement, reduced capacitance, and increased transmission efficiency of photo charges, enhancing the overall performance of the depth sensor.
Implementation Method 1
The sensor may include a plurality of micro-lenses each formed on each of the plurality of photo gate pairs
Implementation Method 2
each of the plurality of first transmission transistors is adapted to transmit charges to the first shared floating diffusion region in response to a first transmission control signal, the charges being generated in the semiconductor substrate under the first photo gate
Data Source
AI summary
A sensor, including a plurality of photo gate pairs on a semiconductor substrate, each of the photo gate pairs including a first photo gate and a second photo gate, a first shared floating diffusion region in the semiconductor substrate, and a plurality of first transmission transistors on the semiconductor substrate, wherein each of the plurality of first transmission transistors is adapted to transmit charges to the first shared floating diffusion region in response to a first transmission control signal, the charges being generated in the semiconductor substrate under the first photo gate of each of the plurality of photo gate pairs.