Image Sensor Pixel With Asymmetric Detection Region Depth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensors, particularly CMOS image sensors, face issues with noise and crosstalk due to electrons generated between adjacent pixels, which degrade image quality and demodulation contrast in time-of-flight systems.
Innovation Solution
The design incorporates pixels with control and detection regions where the depth of the outer detection region is deeper than the inner detection region, preventing electron movement between adjacent pixels and reducing noise and crosstalk without requiring complex isolation processes like deep trench isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If deep trench isolation processes are used to prevent electron movement between adjacent pixels, then crosstalk is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies local quality by creating an asymmetric detection region structure where only the outer detection region has increased depth, while the inner detection region maintains its original depth. This localized structural modification targets specifically the electron collection function at pixel boundaries without requiring complex isolation processes between adjacent pixels, thereby reducing crosstalk while maintaining manufacturing simplicity
Solution Approach 2:
The patent introduces a depth dimension variation in the detection region structure by making the outer detection region deeper than the inner detection region. This vertical dimensional change creates an asymmetric electron collection efficiency that prevents electron movement between adjacent pixels without requiring lateral isolation structures, thus solving the crosstalk problem without increasing manufacturing complexity
2Object-affected harmful factors
If deep trench isolation processes are used for pixel isolation, then crosstalk is reduced, but noise and dark current are generated as side effects
Solution Approach 1:
The patent converts the potentially harmful deep structure modification into a beneficial solution by making the outer detection region deeper, which naturally creates an electron collection asymmetry that prevents crosstalk. This approach avoids the harmful side effects of deep trench isolation processes while still achieving the desired electron isolation effect through structural design rather than aggressive isolation processes
3Object-affected harmful factors
If the detection region depth is increased to prevent electron movement between pixels, then crosstalk is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by creating an asymmetric detection region structure where only the outer detection region has increased depth, while the inner detection region maintains its original depth. This localized structural modification targets specifically the electron collection function at pixel boundaries without requiring complex isolation processes between adjacent pixels, thereby reducing crosstalk while maintaining manufacturing simplicity
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 effectively reduces noise and crosstalk, enhancing the uniformity of demodulation contrast and improving image sensor performance by preventing electron flow between adjacent pixels, thus simplifying the manufacturing process and avoiding side effects like noise or dark current.
Implementation Method 1
a control region configured to generate hole current in a substrate
Implementation Method 2
a detection region configured to capture electrons generated by incident light and moved by the hole current
Data Source
AI summary
A pixel of an image sensor is provided to include a control region and a detection region. The control region is configured to generate hole current in a substrate, and a detection region is configured to capture electrons generated by incident light and moved by the hole current. A depth of an outer detection region of the detection region is deeper than a depth of an inner detection region of the detection region.