Subpixel Isolation Trenches for High-Resolution Image Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors face challenges in maintaining high-quality image capture with reduced pixel sizes, as they struggle to effectively separate and detect different color light wavelengths efficiently.
Innovation Solution
The image sensor design incorporates a substrate with first and second surfaces, featuring first and second pixel isolation trenches, and color unit pixels arranged in a 2×2 matrix, allowing for effective separation and detection of different color light wavelengths, even with reduced pixel sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel size is reduced to increase resolution, then the number of pixels increases, but light separation and detection capability deteriorates
Solution Approach 1:
The pixel isolation structure is divided into multiple segments: first pixel isolation trenches extending in a first direction, second pixel isolation trenches extending in a second direction perpendicular to the first direction, and third pixel isolation trenches extending in a third direction. This multi-directional segmentation effectively separates adjacent pixels and subpixels, preventing light leakage and crosstalk even when pixel sizes are reduced, thereby maintaining reliable light separation capability while enabling higher resolution.
Solution Approach 2:
Different regions of the pixel array are assigned different isolation structures tailored to their specific needs. First color unit pixels contain multiple subpixels (first, second, third, and fourth subpixels) separated by second and third pixel isolation trenches, while second color unit pixels are separated by first pixel isolation trenches. This localized differentiation optimizes light separation for each region, maintaining detection reliability across the entire array despite reduced pixel dimensions.
2Measurement precision
If pixel size is reduced to increase resolution, then the number of pixels increases, but image quality deteriorates
Solution Approach 1:
The comprehensive pixel isolation system using three sets of perpendicular trenches creates well-defined boundaries between pixels and subpixels. This segmentation prevents light from adjacent pixels from interfering with detection, maintaining image quality and color accuracy even when pixels are miniaturized to increase resolution.
3Measurement precision
If pixel size is reduced to increase resolution, then the number of pixels increases, but sensitivity deteriorates
Solution Approach 1:
The second and third pixel isolation trenches within first color unit pixels create compact arrangements of four subpixels that efficiently capture light while maintaining sensitivity. The multi-directional trench structure maximizes the light-receiving area relative to the pixel size, preserving detection sensitivity despite the reduced overall pixel dimensions required for high resolution.
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 enables high-quality image capture by enhancing light separation and detection capabilities, improving sensitivity and resolution while maintaining image quality even with smaller pixel sizes.
Implementation Method 1
A first pixel isolation trench is provided, which is configured to separate the first color unit pixel and the second color unit pixel. A second pixel isolation trench is provided, which is configured to separate the first subpixel and the second subpixel of the first color unit pixel.
Implementation Method 2
typically, an image sensor is configured to generate a digital image of an object using photoelectric conversion elements that react according to the intensity of light reflected from an object
Data Source
AI summary
An image sensor is provided, and the image sensor includes: a substrate having first and second surfaces spaced apart from each other in a vertical direction; a first color unit pixel including a first subpixel to a fourth subpixel arranged in a 2×2 matrix; a second color unit pixel including four subpixels arranged in a 2×2 matrix; a first pixel isolation trench separating the first color unit pixel and the second color unit pixel; a second pixel isolation trench separating the first subpixel and the second subpixel of the first color unit pixel; a third pixel isolation trench on a point of intersection of the first to fourth subpixels of the first color unit pixel. The first color unit pixel detects first color light. The second color unit pixel detects second color light. The image sensor is configured to receive the first color light on the second surface. The second pixel isolation trench extends from the first surface to the second surface. The third pixel isolation trench extends from the second surface to the first surface.