TOF Image Sensor Pixel Structure for Low-Noise Distance Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensing devices face challenges in miniaturization and noise reduction while measuring distance to target objects using the Time of Flight (TOF) method, particularly in integrating efficient detection structures for photocharges without increasing power consumption.
Innovation Solution
The image sensing device incorporates a pixel array with detection nodes having different conductivity types, including doped regions and potential adjustment regions with opposite conductivity types, to optimize photocharge detection and reduce noise, enabling efficient miniaturization and power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If detection structures are integrated for photocharge capture in TOF measurement, then distance measurement capability is improved, but device size and power consumption increase
Solution Approach 1:
The patent combines multiple detection structures (first and second detection structures with different conductivity types) into a single integrated pixel unit, allowing simultaneous photocharge capture and noise reduction without requiring separate dedicated structures, thereby improving distance measurement capability while controlling power consumption
Solution Approach 2:
Each detection node is designed to perform multiple functions: capturing photocharges generated by incident light, reducing noise through opposite conductivity type regions, and contributing to distance measurement. This multi-functionality reduces the need for additional separate components that would increase power consumption
2Measurement precision
If detection structures are integrated for photocharge capture in TOF measurement, then distance measurement capability is improved, but device size increases
Solution Approach 1:
The patent implements a nested structure where potential adjustment regions with opposite conductivity types are embedded within or adjacent to the detection nodes. This nesting allows the detection structures to be compactly arranged within the pixel array, improving distance measurement capability without proportionally increasing device size
Solution Approach 2:
The patent utilizes vertical stacking and three-dimensional arrangement of detection structures with different conductivity types, transitioning from purely two-dimensional planar布局 to incorporating vertical dimension. This allows more functional elements to be packed into a smaller footprint area, improving distance measurement capability while controlling device size
3Measurement precision
If doped regions with opposite conductivity types are used, then noise is reduced and detection accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The patent utilizes changes in conductivity type (from one type to opposite type) as a key parameter modification to reduce noise. By strategically doping regions with opposite conductivity types, the invention achieves noise reduction and improved detection accuracy while the doping processes remain within standard semiconductor manufacturing capabilities
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 configuration enhances the accuracy of distance measurement by reducing noise and power consumption, facilitating the development of compact, high-performance image sensing devices for various applications.
Implementation Method 1
capture photocharges generated by incident light
Implementation Method 2
potential adjustment region overlapping at least a portion of each of the at least one detection node, the potential adjustment region including second conductive impurities different from the first conductive impurities
Data Source
AI summary
An image sensing device includes a first detection structure and a second detection structure, each of the first detection structure and the second detection structure configured to generate a current in a substrate and to capture photocharges generated by incident light and carried by the current, wherein each of the first detection structure and the second detection structure includes: at least one detection node configured to capture the photocharges, the at least one detection node including first conductive impurities; and a potential adjustment region overlapping at least a portion of each of the at least one detection node, the potential adjustment region including second conductive impurities different from the first conductive impurities.