Solid-State Image Sensor Pixel Structure for Charge Transfer Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing solid-state image sensors experience degradation in picture quality due to differences in the movement state of charge generated in the photoelectric conversion portion of adjacent imaging elements, and there is a risk of charge accumulation issues between adjacent elements, leading to characteristic degradation.
Innovation Solution
A solid-state image sensor configuration with imaging element blocks comprising multiple imaging elements, where each element has a first electrode, a charge accumulating electrode, and a photoelectric conversion portion, with the first electrode connected to a connection portion in the interlayer insulating layer, and surrounded by isolation electrodes to ensure smooth charge transfer and prevent movement between adjacent elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If imaging elements are arranged in a stacked configuration with first type and second type photoelectric conversion portions, then multi-color photoelectric conversion capability is improved, but charge transfer uniformity deteriorates due to angle-dependent charge movement variations
Solution Approach 1:
The patent introduces a vertical stacking dimension to accommodate multiple photoelectric conversion portions with different spectral responses. By arranging first type and second type imaging elements at different vertical levels, the system achieves multi-color photoelectric conversion while maintaining uniform charge transfer through carefully designed electrode configurations that account for angular light incidence variations.
Solution Approach 2:
The patent implements equipotential electrode arrangements where the first electrode and charge accumulating electrode are positioned and biased to create uniform potential distributions. This ensures that charges generated at different locations and angles experience consistent electric field conditions, enabling uniform charge transfer despite the stacked configuration's inherent angular variations.
2Measurement precision
If charges are accumulated in photoelectric conversion portions with different absorption coefficients, then spectral selectivity is improved, but charge transfer consistency deteriorates due to angle-dependent movement variations
Solution Approach 1:
The patent applies local quality by assigning different photoelectric conversion materials with specific absorption characteristics to different vertical positions. The first type imaging element uses materials optimized for certain wavelength ranges while the second type uses materials for complementary ranges. Each local region's electrode structure is specifically designed to ensure uniform charge transfer for that particular photoelectric conversion layer's characteristics.
Solution Approach 2:
The patent utilizes parameter changes by varying the absorption coefficients of photoelectric conversion materials across different vertical layers. By selecting materials with complementary absorption spectra and adjusting their thicknesses and positions, the system achieves high spectral selectivity while the electrode potential configuration compensates for angle-dependent transfer variations.
3Quantity of substance
If first electrode and charge accumulating electrode are positioned in spaced relation, then charge accumulation capacity is improved, but charge transfer reliability deteriorates due to potential leakage and uneven transfer
Solution Approach 1:
The patent introduces an interlayer insulating layer as an intermediary between the first electrode and charge accumulating electrode. This insulating layer enables the electrodes to be positioned in spaced relation, increasing charge accumulation capacity through larger separation distances, while simultaneously preventing charge leakage by providing electrical isolation. The insulating layer acts as a mediator that maintains reliable charge transfer through controlled potential distributions.
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 ensures consistent charge movement and transfer within the imaging elements, enhancing the image quality by preventing charge accumulation issues and maintaining sensor characteristics.
Implementation Method 1
a photoelectric conversion portion contacting with the first electrode and formed above the charge accumulating electrode with an insulating layer interposed therebetween
Data Source
AI summary
A solid-state image sensor includes a plurality of imaging element blocks 10 each configured from a plurality of imaging elements. Each of the imaging elements includes a first electrode, a charge accumulating electrode arranged in a spaced relation from the first electrode, a photoelectric conversion portion contacting with the first electrode and formed above the charge accumulating electrode with an insulating layer interposed therebetween, and a second electrode formed on the photoelectric conversion portion. The first electrode and the charge accumulating electrode are provided on an interlayer insulating layer, and the first electrode is connected to a connection portion provided in the interlayer insulating layer.