Junction Field-Effect Transistor Image Sensor Reducing Dark Noise
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Solution Overview
Problem
High-resolution image sensors face challenges with reduced pixel size, leading to increased dark noise and decreased signal-to-noise ratio due to smaller light receiving areas and fewer photons per unit time, making it difficult to obtain clear images.
Innovation Solution
The development of opto-electronic devices with a junction field-effect transistor structure that incorporates a semiconductor substrate, a light receiving unit with quantum dots and a transparent matrix layer, and a driving circuit, which amplifies photocurrent and reduces dark noise by enhancing light-receiving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel size is reduced to increase resolution, then image sensor resolution is improved, but dark noise increases and signal-to-noise ratio decreases
Solution Approach 1:
The light receiving unit is segmented into multiple semiconductor layers with different conductivity types (first semiconductor layer with first conductivity type, second semiconductor layer with second conductivity type), creating a multi-layer junction structure that segments the charge carrier generation and collection paths to reduce dark noise while maintaining small pixel size
Solution Approach 2:
The patent employs composite semiconductor structures combining different materials with distinct electrical properties - the first semiconductor layer (e.g., p-type doped), second semiconductor layer (e.g., n-type doped), and transparent matrix layer form a composite junction field-effect transistor structure that simultaneously achieves high resolution and low dark noise
2Measurement precision
If pixel size is reduced to increase resolution, then image sensor resolution is improved, but signal-to-noise ratio decreases
Solution Approach 1:
The junction field-effect transistor structure segments the semiconductor material into distinct layers (first semiconductor layer, second semiconductor layer separated by transparent matrix layer) that independently handle different aspects of charge carrier generation, separation, and collection, improving signal-to-noise ratio while maintaining small pixel dimensions
Solution Approach 2:
The transparent matrix layer acts as an intermediary between the first and second semiconductor layers, enabling efficient charge carrier separation and transport while maintaining optical transparency, thus improving signal-to-noise ratio in miniaturized pixels
3Measurement precision
If pixel size is reduced, then image sensor resolution is improved, but light receiving area is reduced
Solution Approach 1:
The patent transitions from a planar light receiving structure to a vertical multi-layer junction structure, utilizing the third dimension (depth) to create multiple light receiving interfaces within a small footprint, thereby maintaining effective light receiving area while reducing pixel size for higher 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
The solution effectively reduces dark noise and improves the signal-to-noise ratio, enabling clear image capture even in weak light conditions and allowing for further miniaturization of image sensor pixels while increasing resolution.
Implementation Method 1
a light receiving unit which comprises a first semiconductor layer arranged in an upper region of the semiconductor substrate and doped with a first conductivity type impurity, a second semiconductor layer arranged on the first semiconductor layer and doped with a second conductivity type impurity different from the first conductivity type impurity
Implementation Method 2
a plurality of quantum dots arranged to contact the transparent matrix layer; and a first electrode arranged on a first side of the transparent matrix layer and a second electrode arranged on a second side of the transparent matrix layer opposite to the first side, wherein the first electrode and the second electrode are electrically connected to the second semiconductor layer
Data Source
AI summary
Provided are opto-electronic devices with low dark noise and high signal-to-noise ratio and methods of manufacturing the same. An opto-electronic device may include: a semiconductor substrate; a light receiving unit formed in the semiconductor substrate; and a driving circuit arranged on a surface of the semiconductor substrate. The light receiving unit may include: a first semiconductor layer partially arranged in an upper region of the semiconductor substrate and doped with a first conductivity type impurity; a second semiconductor layer arranged on the first semiconductor layer and doped with a second conductivity type impurity; a transparent matrix layer arranged on an upper surface of the second semiconductor layer; a plurality of quantum dots arranged to contact the transparent matrix layer; and a first electrode and a second electrode electrically connected to the second semiconductor layer and respectively arranged on both sides of the transparent matrix layer.