Image Sensor Element Separation Pattern for Charge Leakage Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensors face challenges in preventing electric charge leakage and void generation in the banding portion of active regions due to the close connection between active areas of transistors and ground regions, which affects image quality and reliability.
Innovation Solution
The image sensor incorporates an element separation pattern that completely separates the first active region, second active region, and ground region, preventing electric charge leakage and minimizing void generation by using a transfer transistor with a transfer gate electrode that partially extends into the substrate and a contact providing ground voltage, ensuring electrical insulation between these regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the active region and ground region are placed close to each other to increase integration density, then the device complexity is reduced, but electric charge leakage occurs between the regions
Solution Approach 1:
The patent divides the semiconductor substrate into distinct regions separated by element separation patterns. These patterns create physical and electrical boundaries between the active region and ground region, allowing them to be placed close together while preventing charge leakage. The segmentation is achieved through insulating structures that partition the substrate into isolated functional zones.
Solution Approach 2:
The element separation pattern acts as an intermediary structure between the active region and ground region. This intermediate layer provides electrical isolation while maintaining spatial proximity, enabling both high integration density and reliable charge containment. The separator functions as a mediator that allows close placement without direct electrical contact.
2Speed
If the transfer gate electrode extends deeply into the substrate to improve charge transfer efficiency, then the speed of charge transfer increases, but void generation in the banding portion increases
Solution Approach 1:
The patent applies different structural characteristics to different regions of the transfer gate electrode. The electrode extends into the substrate in specific areas to enhance charge transfer, while element separation patterns are strategically positioned to prevent void formation in critical banding portions. This local differentiation allows optimized charge transfer without compromising structural integrity.
Solution Approach 2:
The element separation pattern is positioned in advance to prevent void generation before it occurs. By creating preventive barriers in the banding portions before charge transfer operations, the structure cushions against potential void formation, allowing deep electrode extension for improved transfer efficiency without the harmful side effect.
3Reliability
If the element separation pattern is used to separate active region and ground region, then charge leakage is prevented, but the manufacturing process complexity increases
Solution Approach 1:
The element separation pattern serves multiple functions simultaneously: it separates the active region from the ground region to prevent charge leakage, defines the boundaries of the first active region, and provides structural support. By merging these functions into a single integrated structure, the patent reduces the need for additional separate components and simplifies the overall manufacturing process.
Solution Approach 2:
The element separation pattern is designed as a multi-functional structure that performs electrical isolation, region definition, and structural support functions. This universal component eliminates the need for separate elements for each function, thereby reducing manufacturing complexity while maintaining reliable charge leakage prevention.
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 design enhances the reliability and quality of the image sensor by preventing charge leakage and reducing void generation, thereby improving the overall performance and integration density of the image sensor.
Implementation Method 1
the ground region is separated from the transfer gate electrode by the element separation pattern
Implementation Method 2
a photo diode placed in the substrate to be spaced part from the transfer gate electrode
Data Source
AI summary
An image sensor includes a substrate having an element separation pattern, a first active region, and a ground region, the ground region being separated from the first active region by the element separation pattern, a transfer transistor including a transfer gate electrode on the first active region, the transfer gate electrode being separated from the ground region by the element separation pattern, a photo diode within the substrate, the photo diode being spaced apart from the transfer gate electrode, and a contact on the ground region, the contact being configured to receive a ground voltage.