Trench Transfer Gate Electrodes for Image Sensor Charge Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensors face challenges in achieving high-resolution three-dimensional imaging, particularly in distinguishing depth and color pixels effectively, leading to limitations in precision and accuracy in distance calculation and image depth perception.
Innovation Solution
The design incorporates a semiconductor substrate with trenches and transfer gate electrodes, charge-detection layers, and photoelectric conversion layers, where the transfer gate electrodes are positioned between charge-detection layers, allowing for enhanced electric field control and improved charge detection, enabling precise distance calculation and high-resolution three-dimensional imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transfer gate electrodes are positioned in trenches between charge-detection layers, then depth pixel demodulation contrast and charge detection precision are improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The semiconductor substrate is divided into multiple regions with trenches formed to separate and organize transfer gate electrodes and charge-detection layers. This segmentation allows precise spatial positioning of electrodes between charge-detection layers, improving charge detection precision while maintaining manageable device complexity through structured division.
Solution Approach 2:
Transfer gate electrodes are positioned in the vertical dimension between charge-detection layers rather than only in planar arrangements. This three-dimensional positioning within trenches enables enhanced electric field control and charge detection precision by utilizing the vertical space between layers effectively.
2Reliability
If transfer gate electrodes extend further through the semiconductor substrate than charge-detection layers, then electric field control is enhanced, but manufacturing precision requirements increase
Solution Approach 1:
Trenches are formed in the semiconductor substrate before depositing transfer gate electrodes, creating pre-defined pathways that guide electrode positioning. This preliminary structuring ensures that electrodes extend to the required depth through the substrate with consistent positioning, enhancing electric field control while reducing the actual manufacturing precision burden during electrode formation.
3Adaptability or versatility
If multiple transfer gate electrodes are positioned in trenches, then three-dimensional imaging capability is improved, but device complexity increases
Solution Approach 1:
Multiple transfer gate electrodes are segmented and positioned in separate trenches at different locations and depths within the semiconductor substrate. This segmentation enables independent control of each electrode for capturing depth information from different spatial positions, improving three-dimensional imaging capability while organizing complexity through structured spatial division.
Solution Approach 2:
The trench structure serves multiple functions: it provides mechanical support, defines electrode positioning, enables electrical isolation, and facilitates three-dimensional arrangement of multiple electrodes. This multi-functionality reduces the need for additional separate structures, managing device complexity while enabling advanced three-dimensional imaging capabilities.
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 enhances the precision of charge detection and improves the depth pixel's demodulation contrast, resulting in more accurate three-dimensional imaging and better light sensitivity, addressing the limitations of existing image sensors.
Implementation Method 1
a photoelectric conversion layer formed in the semiconductor substrate below the trench
Data Source
AI summary
Provided is an image sensor including a semiconductor substrate having a trench and having a first conductivity type, a photoelectric conversion layer formed in the semiconductor substrate below the trench to have a second conductivity type, first and second transfer gate electrodes provided in the trench covered with a gate insulating layer, a first charge-detection layer formed in the semiconductor substrate adjacent to the first transfer gate electrode, and a second charge-detection layer formed in the semiconductor substrate adjacent to the second transfer gate electrode.