Image Sensor Phase Detection Hafnium Layers
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Solution Overview
Problem
Phase difference auto-focus systems in imaging devices require additional sensors and optical systems, making them costly, while contrast auto-focus systems are less accurate and slower.
Innovation Solution
An image sensor with phase difference detecting pixels that enhance light shielding and electrical insulating properties using hafnium-containing layers, allowing for phase difference-based auto-focusing without additional sensors or optical systems, by forming a pixel array with a light shielding layer and a light transparent layer made of hafnium silicide and hafnium silicate, respectively, which are formed simultaneously to improve optical characteristics and reduce fabrication costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase difference-based auto-focusing is implemented using additional sensors and optical systems, then auto-focusing speed and accuracy are improved, but device cost and complexity increase
Solution Approach 1:
The patent combines phase difference detection functionality with standard image sensor pixels, merging two previously separate systems (phase difference sensor and image sensor) into a single integrated sensor array. This allows phase difference information to be extracted from the same pixel array used for image capture, eliminating the need for dedicated phase difference sensors and reducing overall system complexity while maintaining fast and accurate auto-focusing capability
Solution Approach 2:
The pixel array is designed to serve multiple functions: it acts as both the image sensor for capturing visual information and the phase difference detector for auto-focusing. By making the pixel array universal, the patent eliminates the need for separate dedicated components, thereby reducing device complexity and cost while preserving the speed and accuracy benefits of phase difference-based auto-focusing
2Reliability
If hafnium-containing layers are formed to enhance light shielding and electrical insulating properties, then optical characteristics and phase difference detection are improved, but fabrication process complexity increases
Solution Approach 1:
The patent utilizes variations in oxygen content as a key parameter to differentiate the functionality of hafnium-containing layers. By controlling oxygen concentration during fabrication, the same base material (hafnium) can form layers with different properties: oxygen-deficient regions provide light shielding while oxygen-rich regions provide electrical insulation. This parameter-based differentiation allows multiple functions to be achieved using a single material system, simplifying the overall fabrication process compared to depositing multiple different materials
Solution Approach 2:
The patent employs composite hafnium-based structures where oxygen-deficient hafnium silicide and oxygen-rich hafnium silicate coexist within the same layer system. This composite approach allows simultaneous achievement of light shielding and electrical insulating properties through a single integrated layer structure, reducing the number of separate fabrication steps needed while improving optical characteristics and phase difference detection performance
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
The solution enables fast and accurate phase difference-based auto-focusing without the need for additional sensors or optical systems, improving optical sensing sensitivity, crosstalk characteristics, and phase difference detection, while simplifying the fabrication process and reducing costs.
Implementation Method 1
a light shielding layer formed to contact the substrate corresponding to the light shielding region
Implementation Method 2
a first hafnium-containing layer formed to contact the substrate corresponding to the light shielding region... The first hafnium-containing layer may be in an electrically floating state
Implementation Method 3
a substrate including a photoelectric transformation element having a light receiving region
Data Source
AI summary
An image sensor, comprising: a pixel array in which a plurality of pixels are arranged, wherein at least one of the plurality of pixels includes: a substrate including a photoelectric transformation element having a light receiving region and a light shielding region; and a first hafnium-containing layer formed to contact the substrate corresponding to the light shielding region.