Stacked Photoelectric Conversion Layout With Shared Penetration Electrode
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Solution Overview
Problem
In solid-state image capturing devices, the laminated structure with multiple photodiodes (PDs) leads to a reduction in light entrance surface area due to penetration electrodes, resulting in decreased sensitivity and increased manufacturing costs, along with dark current degradation due to reduced semiconductor substrate crystallinity.
Innovation Solution
A common electric charge accumulation part and penetration electrode are shared between PDs, allowing for efficient light conversion and charge transfer without reducing the light entrance surface area, thereby maintaining sensitivity and reducing manufacturing costs and dark current issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate penetration electrodes and electric charge accumulation parts are provided for each PD, then each PD can be independently connected, but the entrance surface area for light decreases and sensitivity deteriorates
Solution Approach 1:
The patent merges the penetration electrodes and electric charge accumulation parts into shared common structures. Multiple PDs share a single common penetration electrode and a single common electric charge accumulation part, thereby reducing the total number of separate components that would otherwise obstruct light and reducing the overall area occupied by these structures.
2Ease of operation
If separate penetration electrodes are provided for each PD, then each PD can be independently accessed, but the chip area increases and manufacturing cost increases
Solution Approach 1:
The patent combines multiple separate penetration electrodes and electric charge accumulation parts into shared common structures. This merging approach reduces the total chip area occupied by these components while maintaining the functionality of connecting multiple PDs to external circuits.
3Reliability
If separate penetration electrodes are provided for each PD, then each PD can be independently connected, but crystalline defects increase and dark current characteristic degrades
Solution Approach 1:
The patent merges multiple separate penetration electrodes into a single common penetration electrode. This reduces the total number of interfaces where crystalline defects could occur in the semiconductor substrate, thereby reducing the generation of dark current while maintaining the ability to connect multiple PDs.
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 approach prevents the decrease in sensitivity and manufacturing costs associated with the laminated structure, while also minimizing dark current degradation by reducing the number of penetration electrodes through the semiconductor substrate.
Implementation Method 1
a first photoelectric conversion part provided above the semiconductor substrate and configured to convert light into electric charge; and a second photoelectric conversion part provided above the first photoelectric conversion part and configured to convert light into electric charge
Data Source
AI summary
Provided is a solid-state image capturing element including a semiconductor substrate and first and second photoelectric conversion parts configured to convert light into electric charge. The first and the second photoelectric conversion parts each have a laminated structure including an upper electrode, a lower electrode, a photoelectric conversion film sandwiched between the upper electrode and the lower electrode, and an accumulation electrode facing the upper electrode through the photoelectric conversion film and an insulating film. The lower electrode of each of the first and the second photoelectric conversion parts is electrically connected with a common electric charge accumulation part through a common penetration electrode provided in common to the first and the second photoelectric conversion parts and penetrating through the semiconductor substrate, the common electric charge accumulation part being provided in common to the first and the second photoelectric conversion parts in the semiconductor substrate.