Image Sensor Pixel With Isolated Charge Collection Regions

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Solution Overview

Problem

Current image sensors and distance measuring sensors face challenges in accurately measuring distance due to limitations in charge movement and collection between charge collection regions, affecting their accuracy and reliability.

Innovation Solution

The design incorporates a pixel array with a first and second photo gate extending in parallel, a first overflow gate between them, and isolated charge collection regions, where the first overflow gate restricts charge movement between the regions to improve accuracy and reliability by controlling charge transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If charge collection regions are placed in parallel photo gates to enable distance measurement, then distance measuring capability is improved, but charge movement between regions causes measurement inaccuracy

Engineering Contradiction:

Improvedistance measuring capabilityVSAvoiddistance measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The pixel is divided into multiple isolated charge collection regions (first charge collection region and second charge collection region) that are electrically separated. This segmentation prevents charge movement between regions while maintaining parallel photo gate structure for distance measurement capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Isolation structures (such as insulating layers or depletion regions) are introduced between the first and second charge collection regions to prevent charge movement. These intermediary elements act as barriers that maintain electrical separation while allowing both regions to function independently for accurate distance measurement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple charge collection regions are integrated in a single pixel for depth imaging, then three-dimensional imaging capability is improved, but charge interference between regions reduces sensor reliability

Engineering Contradiction:

Improvethree-dimensional imaging capabilityVSAvoidsensor reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The single pixel is segmented into multiple independent charge collection regions with distinct electrical isolation. This allows each region to collect charges independently without interference, ensuring reliable operation while enabling three-dimensional imaging through depth information from multiple regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions within the pixel are given different specialized functions through local structural variations and isolation mechanisms. The first charge collection region and second charge collection region have distinct electrical characteristics and isolation configurations optimized for their specific roles in depth imaging.

Inventive Principle:

Principle #3Local quality

3Use of energy by moving object

If photo gates are extended in parallel to increase light reception area, then light sensitivity is improved, but charge crosstalk between gates increases

Engineering Contradiction:

Improvelight sensitivityVSAvoidcharge crosstalk

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

Isolation structures are positioned between the first photo gate and second photo gate to prevent charge crosstalk. These intermediary elements act as electrical barriers that maintain independence between the extended parallel photo gates while preserving their increased light reception area and sensitivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 accuracy and reliability of distance measurement by effectively managing charge movement and collection, leading to improved performance in image sensing and distance measurement applications.

Implementation Method 1

Image sensors include semiconductor devices that may convert an optical image, including incident light, into an electrical signal

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS11525922B2Image sensors and distance measuring devices using the same

Publication Date: 2022.12.13 SAMSUNG ELECTRONICS CO LTD

AI summary

An image sensor may include a first photo gate and a second photo gate each extending substantially in parallel in a first direction, the first photo gate and the second photo gate isolated from direct contact with each other in a second direction, the second direction substantially orthogonal to the first direction, a first overflow gate between the first photo gate and the second photo gate, the first overflow gate extending in the first direction, a first charge collection region on the first photo gate, a second charge collection region on the second photo gate and isolated from direct contact with the first charge collection region in the second direction, a first floating diffusion region that may receive first charge from the first charge collection region and output the first charge, and a second floating diffusion region that may receive second charge from the second charge collection region and output the second charge.