Solid-State Imaging Pixel Layout for Charge-Holding Light Shielding
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Solution Overview
Problem
In solid-state imaging units, noise is caused by light entering the charge holding section, which existing technologies have not effectively addressed.
Innovation Solution
A solid-state imaging unit is designed with two or more light-blocking sections disposed between the light receiving surface and the charge holding section, these sections being different and positioned to block light entry into the charge holding section without creating a gap, ensuring that light does not interfere with the photoelectric conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light-blocking section is provided between the photoelectric conversion section and the charge holding section, then light entry into the charge holding section is prevented, but the structural complexity increases and may block necessary light paths
Solution Approach 1:
The light-blocking function is divided into multiple light-blocking sections (first light-blocking section 53 and second light-blocking section 56) positioned at different locations. This segmentation allows each section to block light from specific directions while maintaining transparency in other areas, preventing complete light path obstruction and reducing the harmful effect of light entry into the charge holding section.
Solution Approach 2:
The light-blocking sections are designed with local quality by creating specific transparent regions (opening 53H in the first light-blocking section and opposing transparent region in the second light-blocking section) that allow light to pass through where needed. This enables selective light blocking - preventing light entry into the charge holding section while maintaining necessary light paths for photoelectric conversion.
2Object-affected harmful factors
If multiple light-blocking sections are provided in different layers, then light blocking effectiveness is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The light-blocking sections are nested within the pixel structure at different layers. The first light-blocking section 53 is positioned between the color filter 37 and the charge holding section MEM, while the second light-blocking section 56 is positioned between the first light-blocking section 53 and the charge holding section MEM. This nested arrangement provides multi-layer light blocking without significantly increasing manufacturing complexity, as each layer can be integrated into the existing pixel structure.
3Object-affected harmful factors
If light-blocking sections are positioned to completely block light entry, then noise is reduced, but light blocking of the photoelectric conversion section may occur
Solution Approach 1:
The light-blocking sections are designed with local quality by creating specific transparent regions (opening 53H in the first light-blocking section and opposing transparent region in the second light-blocking section) that allow light to pass through where needed. This enables selective light blocking - preventing light entry into the charge holding section while maintaining necessary light paths for photoelectric conversion.
Solution Approach 2:
The light-blocking function is divided into multiple light-blocking sections (first light-blocking section 53 and second light-blocking section 56) positioned at different locations. This segmentation allows each section to block light from specific directions while maintaining transparency in other areas, preventing complete light path obstruction and reducing the harmful effect of light entry into the charge holding section.
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 effectively reduces noise by preventing light from entering the charge holding section, thereby improving image quality and reducing unwanted signal interference.
Implementation Method 1
The photoelectric conversion section performs photoelectric conversion on light having entered via the light receiving surface
Implementation Method 2
The two or more light-blocking sections are provided at positions at which the two or more light-blocking sections do not block entry, into the photoelectric conversion section, of the light having entered via the light receiving surface
Data Source
AI summary
A solid-state imaging unit according to one embodiment of the present disclosure includes two or more pixels. The pixels each include a photoelectric conversion section, a charge holding section, and a transfer transistor. The charge holding section holds a charge transferred from the photoelectric conversion section. The transfer transistor transfers the charge from the photoelectric conversion section to the charge holding section. The pixels each include two or more light-blocking sections disposed in layers between the light receiving surface and the charge holding section and are different from each other. The two or more light-blocking sections are provided at positions at which the two or more light-blocking sections do not block entry, into the photoelectric conversion section, of the light having entered via the light receiving surface and at which the two or more light-blocking sections do not provide a gap when viewed from the light receiving surface.