Imaging Device Dark Signal Control via Localized Contact Sizing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices face challenges in effectively controlling dark signal levels, leading to image quality degradation due to variations in dark signal shading and Optical Black (OPB) level differences, which current methods attempt to address but often result in complicated techniques or decreased image quality.
Innovation Solution
The implementation of an imaging device with semiconductor-based ground contacts of varying sizes to connect light-receiving portions and electrically conductive wirings, allowing for precise control of dark signal levels without affecting image quality, by differentiating contact sizes between effective pixel and Optical Black regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gate area of an amplifier transistor is adjusted to control dark signal, then dark signal level is improved, but mutual conductance decreases or short channeling occurs leading to gain variability
Solution Approach 1:
The patent applies local quality by differentiating contact sizes specifically in the Optical Black region versus the effective pixel region. Ground contacts in the Optical Black region are designed with different dimensions (larger or smaller area) compared to those in the effective pixel region, allowing localized control of dark signal characteristics without affecting the overall transistor performance uniformly across the device.
2Manufacturing precision
If conversion efficiencies are adjusted through wiring pattern or diffusion layer changes to control dark signal, then dark signal level is improved, but image capturing characteristics at bright state deteriorate
Solution Approach 1:
The patent implements local quality by applying different contact sizes specifically to the Optical Black region while maintaining standard contact sizes in the effective pixel region. This localized differentiation allows dark signal control in the Optical Black area without modifying the imaging characteristics of the effective pixels, thus preserving image quality at bright states.
3Manufacturing precision
If sensor potentials are changed to control dark signal, then dark signal level is improved, but readout voltage and sensitivity are greatly affected leading to degraded image quality
Solution Approach 1:
The patent applies local quality by restricting the contact size modification to the Optical Black region only, while keeping the effective pixel region unchanged. This ensures that dark signal control is achieved locally without globally affecting sensor potentials, readout voltage, or sensitivity, thereby maintaining overall image quality.
4Manufacturing precision
If P+ ions are implanted at high concentration around pixel ground contact to control dark signal, then dark signal level is improved, but white dots or dark electric current occur and saturation characteristics deteriorate
Solution Approach 1:
The patent implements local quality by differentiating contact sizes specifically in the Optical Black region where dark signal control is needed, rather than applying high concentration P+ ion implantation universally. This localized approach achieves dark signal control without generating white dots or dark electric current in the effective pixel regions.
5Manufacturing precision
If pixel extension region is greatly enlarged to suppress dark signal shading, then dark signal uniformity is improved, but chip size increases leading to decreased production yield
Solution Approach 1:
The patent applies local quality by implementing contact size differentiation specifically in the Optical Black region, which suppresses dark signal shading effects without requiring a global enlargement of the pixel extension region. This maintains dark signal uniformity while keeping the chip size compact and production yield high.
6Manufacturing precision
If additional memories are added for signal process to correct OPB level difference, then correction capability is improved, but noise increases leading to degraded image quality
Solution Approach 1:
The patent implements local quality by using different contact sizes in the Optical Black region to directly control and equalize dark signal levels at the hardware level. This prevents OPB level differences before they occur, eliminating the need for additional memory-based signal processing and avoiding the introduction of noise.
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 enables appropriate and easy control of dark signal levels, reducing variability and maintaining high image quality without increasing production complexity or costs, thus improving image capture capabilities.
Implementation Method 1
a light-receiving portion that performs photoelectric conversion of incident light
Data Source
AI summary
There is provided an imaging device including a semiconductor having a light-receiving portion that performs photoelectric conversion of incident light, electrically conductive wirings, and a contact group including contacts that have different sizes and connect the semiconductor and the electrically conductive wirings.