Shield Electrode Structure for Crosstalk Reduction in Imaging Devices
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Solution Overview
Problem
Lamination type imaging devices suffer from carrier crosstalk and color crosstalk due to the lack of compartmentalization in photoelectric conversion films, leading to inefficiencies in signal charge management between pixels.
Innovation Solution
The implementation of a shield electrode structure where a shield voltage is applied to the shield electrode, which is lower than the initialization voltage, effectively separates signal charges and reduces crosstalk by creating a charge capture region that captures holes generated through photoelectric conversion, thereby suppressing crosstalk between adjacent pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shield electrode is provided to surround a pixel electrode and connected to ground, then crosstalk between pixels is reduced, but device complexity increases
Solution Approach 1:
The imaging device is divided into multiple unit pixel cells, with each pixel cell containing its own pixel electrode and shield electrode structure. This segmentation isolates the electrical fields of adjacent pixels, preventing carrier crosstalk while maintaining a relatively simple overall structure through modular design.
Solution Approach 2:
The shield electrode acts as an intermediary element between adjacent pixel electrodes. By positioning the shield electrode between pixels and applying appropriate voltages, it mediates the electrical field distribution and prevents direct interaction between signal charges of adjacent pixels, reducing crosstalk without requiring complete structural isolation.
2Ease of manufacture
If the photoelectric conversion film is integrally formed throughout multiple unit pixel cells, then manufacturing is simplified, but carrier crosstalk and color crosstalk occur
Solution Approach 1:
The patent applies local quality by introducing pixel-specific voltage control to locally formed photoelectric conversion films. Each pixel electrode can apply different voltages to create localized charge capture regions, ensuring that signal charges are captured only by their intended pixel electrode. This maintains the manufacturing simplicity of integral film formation while achieving effective charge separation and crosstalk reduction through localized electrical field control.
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 suppression of crosstalk, allowing for more accurate signal detection and improved sensitivity by actively directing and capturing signal charges, thereby reducing carrier and color crosstalk between pixels.
Implementation Method 1
charges are generated through photoelectric conversion
Implementation Method 2
a shield voltage being applied to the shield electrode, which is lower than the initialization voltage, effectively separates signal charges and reduces crosstalk by creating a charge capture region that captures holes
Data Source
AI summary
An imaging device including at least one pixel, where each of the at least one pixels includes a photoelectric conversion layer having a first surface and a second surface being on a side opposite to the first surface; a first electrode located on the first surface; a second electrode located on the first surface, the second electrode being separated from the first electrode, a first voltage being applied to the second electrode; a third electrode located on the second surface, the third electrode opposing to the first electrode and the second electrode, a second voltage being applied to the third electrode; and an amplifier transistor having a gate electrically connected to the first electrode, where an absolute value of a difference between the first voltage and the second voltage is larger than an absolute value of a difference between the second voltage and a voltage of the first electrode.