Photoelectric Detection Pixel Capacitor Layout for Stable Signal Output
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Solution Overview
Problem
Existing detection devices experience variations in signal output due to fluctuations in potential at the node during the exposure period between reset and read periods, affecting the reliability and consistency of the detection process.
Innovation Solution
The detection device incorporates a capacitor structure formed by first and second electrodes, where the first electrode is in the same layer as the gate electrode and the second electrode is in the same layer as the semiconductor layer, with an island pattern for each photoelectric conversion element, to stabilize the potential at the node by adding an additional capacitor Cad, reducing variations in signal output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional transistor-driven photoelectric conversion device is used, then the device structure is simple, but the signal output shows significant variation due to potential fluctuations during exposure
Solution Approach 1:
The capacitor structure is nested within the existing transistor and photoelectric conversion element architecture. The first electrode is positioned in the same layer as the gate electrode, and the second electrode is positioned in the same layer as the semiconductor layer, allowing the capacitor to be integrated without adding significant structural complexity while effectively stabilizing the node potential and reducing signal variation
Solution Approach 2:
The capacitor is implemented by utilizing the vertical layering already present in the device structure. By placing electrodes in existing layers (gate electrode layer and semiconductor layer) and using the insulating film between them, the invention adds a capacitive function in the vertical dimension without requiring additional horizontal space or complex routing
2Ease of manufacture
If the first electrode is placed in the same layer as the gate electrode and the second electrode in the same layer as the semiconductor layer, then the capacitor integrates well with existing structures, but manufacturing precision requirements increase
Solution Approach 1:
The insulating film that naturally exists between the gate electrode layer and semiconductor layer in the transistor structure is repurposed as the capacitor dielectric. This multi-functional use of existing layers eliminates the need for separate capacitor fabrication processes and reduces alignment requirements, as the capacitor electrodes automatically align with the transistor structure
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 signal variations by maintaining consistent potential during the exposure period, enhancing the reliability and accuracy of the detection process.
Implementation Method 1
a plurality of photoelectric conversion elements arranged on the substrate
Implementation Method 2
a first electrode and a second electrode that are provided between the substrate and the photoelectric conversion elements in a direction orthogonal to the substrate and face each other with an insulating film interposed between the first electrode and the second electrode
Data Source
AI summary
According to an aspect, a detection device includes: a substrate; photoelectric conversion elements arranged on the substrate; transistors that each include a semiconductor layer and a gate electrode facing the semiconductor layer and are provided for each photoelectric conversion element; and a first electrode and a second electrode that are provided between the substrate and the photoelectric conversion elements in a direction orthogonal to the substrate and face each other with an insulating film interposed therebetween. The first electrode includes main parts that overlap the respective photoelectric conversion elements and a coupling part couples together adjacent main parts of the main parts. The second electrode is formed to have an island pattern for each photoelectric conversion element. The first electrode is located in the same layer as that of the gate electrode. The second electrode is located in the same layer as that of the semiconductor layer.