Shared Pixel Image Sensor Layout for Higher Full Well Capacity

Solution Overview

Problem

The reduction in pixel sizes in image sensors impedes the formation of uniform patterns of isolation layers and doped well patterns, affecting the full well capacity (FWC) and image quality.

Innovation Solution

The image sensor design includes a substrate with shared pixel regions, isolation layers, and well regions doped with conductivity type impurities, allowing for uniform formation of sub-pixel regions and increased FWC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pixel sizes are reduced to increase resolution, then image resolution is improved, but uniform formation of isolation layers and doped well patterns becomes difficult

Engineering Contradiction:

Improveimage resolutionVSAvoiduniformity of isolation layers and doped well patterns

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The pixel array is divided into first pixel regions and second pixel regions with different structures. The first pixel regions contain first photo-sensing devices with first isolation layers and first doped well patterns, while the second pixel regions contain second photo-sensing devices with second isolation layers and second doped well patterns. This segmentation allows each region to be optimized independently for uniform pattern formation despite overall pixel size reduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different pixel regions are designed with different local characteristics - first pixel regions have first isolation layers and first doped well patterns with specific dimensions and doping concentrations, while second pixel regions have second isolation layers and second doped well patterns with different dimensions and doping concentrations. This local quality variation enables each region to maintain uniform pattern formation while accommodating reduced overall pixel sizes.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If pixel sizes are reduced to increase resolution, then image resolution is improved, but full well capacity decreases

Engineering Contradiction:

Improveimage resolutionVSAvoidfull well capacity

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

Different pixel regions are designed with different local characteristics - first pixel regions have first isolation layers and first doped well patterns with specific dimensions and doping concentrations, while second pixel regions have second isolation layers and second doped well patterns with different dimensions and doping concentrations. This local quality variation enables each region to maintain uniform pattern formation while accommodating reduced overall pixel sizes.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If different pixel regions have different structures to ensure uniform pattern formation, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:

Improveuniformity of isolation layers and doped well patternsVSAvoidstructural complexity of pixel regions

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The pixel array is divided into first pixel regions and second pixel regions with different structures. The first pixel regions contain first photo-sensing devices with first isolation layers and first doped well patterns, while the second pixel regions contain second photo-sensing devices with second isolation layers and second doped well patterns. This segmentation allows each region to be optimized independently for uniform pattern formation despite overall pixel size reduction.

Inventive Principle:

Principle #1Segmentation

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 design enhances the full well capacity and ensures uniform patterns of isolation and well regions, improving image quality and resolution.

Implementation Method 1

The first shared pixel region may include a plurality of photo-sensing devices in a plurality of sub-pixel regions

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

The first shared pixel region may include a first well region doped with first conductivity type impurities and a second well region doped with the first conductivity type impurities

Methodology Applied

Scientific EffectElectrostatic field: Electric Field

Data Source

PatentUS12328961B2Image sensor including shared pixels

Publication Date: 2025.06.10 SAMSUNG ELECTRONICS CO LTD

AI summary

An image sensor may include a first shared pixel region and a first isolation layer on a substrate, the first isolation layer defining the first shared pixel region. The first shared pixel region may include photo-sensing devices in sub-pixel regions and a first floating diffusion region connected to the photo-sensing devices. The sub-pixel regions may include a first sub-pixel region and a second sub-pixel region that constitute a first pixel group region. The sub-pixel regions may include a third sub-pixel region and a fourth sub-pixel region that constitute a second pixel group region. The first shared pixel region may include first and second well regions doped with first conductivity type impurities. The second well region may be spaced apart from the first well region. The first pixel group region may share a first well region. The second pixel group region may share the second well region.