Solid-State Imaging Device Crosstalk Suppression via Locally Thin Substrate
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Solution Overview
Problem
Solid-state imaging devices face challenges in suppressing crosstalk between adjacent pixels due to electrical leakage, particularly with techniques involving wires for potential control and shield electrodes, which complicate manufacturing and can result in leakage currents.
Innovation Solution
A solid-state imaging device is designed with a substrate featuring a locally thin region and an interlayer insulating film that extends into this region, along with electrodes and a photoelectric conversion layer, to reduce dielectric constant and increase the potential barrier between pixels, thereby minimizing leakage currents and crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wire for potential control and insulating film are provided between adjacent pixel electrodes to suppress crosstalk, then signal leakage between pixels is reduced, but manufacturing processes become complicated and the number of processes increases
Solution Approach 1:
The invention extracts and eliminates the need for additional potential control wires and insulating films by utilizing the substrate's inherent properties. The locally thin region in the substrate itself provides the necessary electrical isolation and potential barrier, removing the need for separate control structures and simplifying the device architecture.
Solution Approach 2:
The substrate is designed with a locally thin region specifically positioned between adjacent pixels. This localized structural modification creates different electrical properties in different regions of the substrate, providing enhanced potential barriers and capacitive isolation exactly where needed between pixels without affecting the overall device structure.
2Reliability
If a shield electrode is provided between adjacent pixels to decrease capacitive coupling, then crosstalk is reduced, but leakage current is generated between the pixel electrode and the shield electrode
Solution Approach 1:
The invention converts the substrate's capacitance, which could potentially cause coupling, into a beneficial element. By creating a locally thin region, the substrate provides controlled capacitive coupling that actually helps establish potential barriers and reduce leakage currents, transforming a potential harmful effect into a useful mechanism for crosstalk suppression.
Solution Approach 2:
The invention changes the physical parameter of the substrate thickness in a localized region. This parameter change modifies the electrical characteristics, creating different capacitance values and potential barrier heights in different regions, which effectively suppresses both capacitive coupling and leakage currents simultaneously.
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 suppresses leakage currents and crosstalk between adjacent pixels by reducing the voltage drop in the photoelectric conversion layer and increasing the potential barrier, simplifying the manufacturing process while maintaining image sensor performance.
Implementation Method 1
electrical leakage between adjacent pixels is caused by capacitive coupling through the photoelectric conversion film
Implementation Method 2
a region between adjacent pixels having a reduced dielectric constant
Implementation Method 3
a photoelectric conversion layer at least partially between the first electrode and the second electrode
Data Source
AI summary
Solid-state imaging devices, electronic apparatuses, and methods of forming image sensors are provided. A solid-state imaging device or an electronic apparatus incorporating a solid-state imaging device can include a substrate and at least a first photoelectric conversion element formed in the substrate. In addition, a region with a low dielectric constant is formed. The region can include a locally thin region formed in the substrate. An insulating film is at the first side of the substrate. Where the region includes a locally thin region, the interlayer insulating film can extend into that locally thin region. A first electrode is at a side of the interlayer insulating film opposite the substrate. The device further includes a second electrode, and a photoelectric conversion layer at least partially between the first electrode and the second electrode.