Image Sensor Stacked Color Filter Wavelength Selectivity
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Solution Overview
Problem
There is a need for image sensors with improved sensitivity and reduced size, as existing image sensors face challenges in wavelength selectivity and crosstalk, particularly in capturing mixed light from multiple colors efficiently.
Innovation Solution
The image sensor incorporates a semiconductor substrate with photo-sensing devices and a color filter layer that includes multiple photoelectric conversion devices and color filters arranged to selectively transmit and absorb light of different colors, allowing for enhanced wavelength selectivity and reduced crosstalk by optimizing the arrangement of color filters and light-absorption layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional image sensor structure is used, then the device can capture images, but the wavelength selectivity is insufficient and crosstalk between colors occurs
Solution Approach 1:
The color filter layer is segmented into multiple distinct color filters (first color filter, second color filter, third color filter) arranged in a specific pattern. Each color filter selectively transmits specific wavelength ranges, dividing the incident light into separate color channels to improve wavelength selectivity and reduce crosstalk between colors.
Solution Approach 2:
Different regions of the color filter layer have different optical properties tailored to their specific functions. The first color filter transmits blue and green light while absorbing red, the second color filter transmits green and red light while absorbing blue, and the third color filter transmits all three colors. This local differentiation of optical characteristics enhances overall wavelength selectivity.
2Area of stationary object
If the image sensor size is reduced, then compactness is improved, but sensitivity and light-absorption efficiency deteriorate
Solution Approach 1:
The patent transitions from a planar arrangement to a three-dimensional stacked structure where the color filter layer is positioned above the photoelectric conversion layer. This vertical stacking allows for more efficient use of space, reducing the overall sensor area while maintaining adequate light-absorption efficiency through optimized layer thicknesses and material properties.
Solution Approach 2:
The image sensor employs composite material structures including multiple layers with different optical and electrical properties. The color filters are integrated with the photoelectric conversion layer in a stacked configuration, creating a composite structure that achieves both compactness and high sensitivity by optimizing the interaction between different materials at the nanoscale.
3Measurement precision
If color filters are added to improve wavelength selectivity, then crosstalk is reduced, but device complexity increases
Solution Approach 1:
The color filter layer and photoelectric conversion layer are merged into a single integrated stacked structure rather than being separate components. This merging reduces overall device complexity by consolidating multiple functions into one compact unit while maintaining the wavelength-selective properties of the color filters.
Solution Approach 2:
The stacked structure serves multiple functions simultaneously: the color filters provide wavelength selection, the intermediate layer enables light transmission and electrical connection, and the photoelectric conversion layer converts light to electrical signals. This multi-functionality reduces the need for additional separate components, thereby reducing overall device complexity.
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 increases light-absorption efficiency, reduces crosstalk, and enables a more compact image sensor design by effectively handling mixed light from multiple colors, improving sensitivity and luminance while minimizing current loss.
Implementation Method 1
a photoelectric conversion device disposed on the semiconductor substrate and absorbing mixed light of a first color and a second color
Implementation Method 2
a color filter disposed on one side of the photoelectric conversion device and configured to selectively transmit a mixed light including a third color
Data Source
AI summary
An image sensor includes a semiconductor substrate including a plurality of photo-sensing devices, a photoelectric conversion device disposed on the semiconductor substrate and absorbing the mixed light of a first color and a second color, and a color filter disposed on one side of the photoelectric conversion device and configured to selectively transmit a mixed light including a third color, and an electronic device including the image sensor is provided.