X-Ray Light-Receiving Pixel Guard Ring for Uniform Potential

Solution Overview

Problem

X-ray imaging devices face challenges in reducing dispersion of pixel characteristics across the entire surface of a pixel array, leading to issues such as fluctuation in potential and degradation of signal charge transfer and leak current.

Innovation Solution

A light-receiving device with a semiconductor substrate featuring a light-receiving region and a peripheral region, including specific electrically-conductive regions such as a pixel edge guard ring and an embedded layer, which are designed to reduce potential fluctuations and maintain consistent electric potential across the array.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple structure with integrated photoelectric conversion region and floating diffusion region is used, then ease of manufacture is improved, but dispersion of pixel characteristics across the light-receiving region increases

Engineering Contradiction:

Improveease of manufactureVSAvoidpixel characteristic uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing a pixel edge guard ring structure specifically at the peripheral region of the light-receiving element, while the central region maintains the simple integrated structure. This localized modification addresses the pixel characteristic dispersion issue at edges without complicating the overall manufacturing process, thereby resolving the contradiction between ease of manufacture and pixel characteristic uniformity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The pixel edge guard ring is designed to maintain equipotential conditions at the peripheral region of the light-receiving element. By creating an electrically conductive ring structure at the edge, the patent equalizes the potential distribution across the light-receiving region, reducing potential fluctuations and minimizing dispersion of pixel characteristics while preserving the simple integrated structure.

Inventive Principle:

Principle #12Equipotentiality

2Measurement precision

If the photoelectric conversion region thickness is increased to improve sensitivity, then measurement precision is improved, but potential fluctuation at peripheral light-receiving elements increases

Engineering Contradiction:

ImprovesensitivityVSAvoidpotential stability

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by introducing a pixel edge guard ring structure specifically at the peripheral region of the light-receiving element, while the central region maintains the simple integrated structure. This localized modification addresses the pixel characteristic dispersion issue at edges without complicating the overall manufacturing process, thereby resolving the contradiction between ease of manufacture and pixel characteristic uniformity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The pixel edge guard ring is designed to maintain equipotential conditions at the peripheral region of the light-receiving element. By creating an electrically conductive ring structure at the edge, the patent equalizes the potential distribution across the light-receiving region, reducing potential fluctuations and minimizing dispersion of pixel characteristics while preserving the simple integrated structure.

Inventive Principle:

Principle #12Equipotentiality

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

The solution effectively reduces potential fluctuations and maintains consistent pixel characteristics, preventing degradation and improving signal charge transfer and reducing leak current in X-ray imaging devices.

Implementation Method 1

a light-receiving device according to an embodiment of the present disclosure includes: a semiconductor substrate including a light-receiving region in which a plurality of light-receiving elements are arranged two-dimensionally in matrix

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS20250006768A1Light-receiving device, x-ray imaging device, and electronic apparatus

Publication Date: 2025.01.02 SONY SEMICON SOLUTIONS CORP

AI summary

A light-receiving device of an embodiment of the disclosure includes: a semiconductor substrate including a light-receiving region with light-receiving elements arranged two-dimensionally in matrix, and a peripheral region provided therearound; a first first electrically-conductive region provided at an interface of a first surface of the semiconductor substrate for each element and coupled to a first electrode, in the light-receiving region; a second first electrically-conductive region provided around the first first region provided for each element and coupled to a second electrode, at the interface; a third first electrically-conductive region provided around the second first region provided for each element and having electrically floating state, at the interface;a fourth first electrically-conductive region provided at the interface around the light-receiving region and having electrically floating state, in the peripheral region; and a first second electrically-conductive region embeddedly formed in the semiconductor substrate and facing the second, third, and fourth first regions.