Buried Diode Isolation via High Concentration Intermediary Regions
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Solution Overview
Problem
Existing imaging devices with buried diode structures lack effective isolation properties between neighboring buried diodes, leading to signal crosstalk and reduced pixel integration, particularly in imaging devices with global electronic shutter functions.
Innovation Solution
The implementation of a method to manufacture imaging devices with buried diodes by strategically implanting impurity ions to create semiconductor regions with varying conductivity types and concentrations, forming a high concentration p-type semiconductor region between neighboring photoelectric conversion portions to enhance isolation, and utilizing these regions as inter-pixel isolation and well contacts to reduce leakage and contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If buried diode structures are used for photoelectric conversion portions and charge holding portions, then white flaw defects are suppressed and global electronic shutter function is enabled, but isolation performance between neighboring buried diodes deteriorates leading to signal crosstalk
Solution Approach 1:
An intermediary semiconductor region (fifth semiconductor region) with higher impurity concentration is introduced between neighboring buried diodes. This intermediate structure acts as a barrier that prevents signal crosstalk while maintaining the buried diode configuration for white flaw suppression and global electronic shutter function.
Solution Approach 2:
The impurity concentration is locally increased in the semiconductor region between neighboring buried diodes (fifth semiconductor region). This local modification of material properties enhances isolation performance specifically where needed, without altering the overall buried diode structure.
2Adaptability or versatility
If buried diode structures are used for photoelectric conversion portions and charge holding portions, then global electronic shutter function is enabled, but isolation property between elements deteriorates
Solution Approach 1:
The fifth semiconductor region with higher impurity concentration serves as an intermediary barrier between photoelectric conversion portions and charge holding portions. This intermediate structure prevents signal leakage while enabling the global electronic shutter function through the buried diode configuration.
3Productivity
If high integration of pixels is implemented, then pixel density increases, but isolation performance between elements deteriorates
Solution Approach 1:
Local quality enhancement through increased impurity concentration in the fifth semiconductor region provides effective isolation even when pixels are highly integrated. This localized modification allows high pixel density while preventing signal crosstalk between neighboring elements.
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 improves the isolation performance between buried diodes without complicating the manufacturing process, effectively suppressing signal crosstalk and enhancing the integration of pixels, thereby improving image quality and reducing dark state noise.
Implementation Method 1
implanting first impurity ions of the first conductivity type into the first region and a third region between the first region and the second region, and implanting second impurity ions of the first conductivity type into the second region and the third region
Data Source
AI summary
A method of manufacturing an imaging device, including a first buried diode including a first semiconductor region and a second semiconductor region and a second buried diode including a third semiconductor region and a fourth semiconductor region, includes implanting first impurity ions of a first conductivity type into a first region and a third region between the first region and a second region, and implanting second impurity ions of the first conductivity type into the second region and the third region, wherein the first semiconductor region is formed by implanting the first impurity ions, the third semiconductor region is formed by implanting the second impurity ions, and a fifth semiconductor region having a higher impurity concentration than the first and the second semiconductor regions is formed in the third region by implanting the first and second impurity ions.