Charge-Transfer Sensor Eliminating Potential Barriers

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Solution Overview

Problem

Existing chemical/physical phenomenon detection devices face challenges in high integration density and sensitivity due to potential barriers caused by remaining charges, which generate false signals and hinder accurate measurement of external changes like pH levels.

Innovation Solution

A chemical/physical phenomenon detection device is designed without a second charge control electrode or wiring, utilizing a doped diffusion layer between the input charge control and sensing regions to eliminate the potential barrier, allowing for high-density integration and improved sensitivity by ensuring no charge presence in the diffusion layer, thus preventing false signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a charge removal well and second charge control electrode are added to eliminate the potential barrier, then sensitivity and false signal prevention are improved, but device complexity and integration density are worsened

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the root cause of the potential barrier by removing the thick silicon nitride film coverage from the first charge control electrode through selective etching. This extraction approach removes the source of the problem rather than adding complex compensation structures, thereby improving sensitivity without increasing device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary step in the manufacturing process - selective etching of the silicon nitride film - to create a localized opening that allows the first charge control electrode to control the potential at the interface. This intermediary modification enables potential barrier elimination without requiring additional control electrodes or complex wiring

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a charge removal well is provided to remove remaining charges, then false signal generation is prevented, but the potential barrier influence is not fully eliminated and device integration is reduced

Engineering Contradiction:
Improvefalse signal preventionVSAvoidintegration density
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention performs preliminary action by eliminating the potential barrier at the source during the manufacturing process through selective etching. By preventing the potential barrier formation beforehand, the device inherently prevents false signal generation without requiring additional charge removal structures, thereby maintaining high integration density

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention converts the potentially harmful thick silicon nitride film coverage into a benefit by selectively removing it only where needed. The selective etching process transforms the film from a source of potential barriers into a controlled structure that enables proper electrode functionality while maintaining protection in other areas

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 enables high-density integration and enhanced sensitivity by eliminating the potential barrier, allowing for precise measurement of external changes without false signals, specifically in pH detection, and simplifies the manufacturing process by using the same dopant for multiple regions.

Implementation Method 1

a diffusion layer (4) formed between the input charge control region (3) and the sensing region (5) in which no charge is present

Methodology Applied
Scientific EffectDoping: Dopants

Implementation Method 2

the potential in a neutral state of the diffusion layer is depart form or got off the potential of the sensing region. As a result of the doped diffusion layer, no potential barrier is formed between the charge supply control region and the sensing region

Methodology Applied
Scientific EffectPotential barrier elimination: Electric Field

Data Source

PatentEP3246699B1Device for detecting chemical/physical phenomenon
Publication Date: 2019.04.17 TOYOHASHI UNIVERSITY OF TECHNOLOGY
  • EP3246699B1 patent drawingFigure 1~2
  • EP3246699B1 patent drawingFigure 3
  • EP3246699B1 patent drawingFigure 4(a)~4(g)

AI summary

Provided is a charge-transfer-type sensor suitable for high integration while eliminating a potential barrier. A sensor provided with a semiconductor substrate 10 partitioned into a sensing region 5 in which a potential varies in corresponding fashion to a variation in the external environment, a charge input region 2 for supplying charges to the sensing region 5, an input charge control region 3 interposed between the sensing region 5 and the charge input region 2, and a charge accumulation region 7 for accumulating electric charges transported from the sensing region 5, the sensor for detecting the amount of electric charges accumulated in the charge accumulation region 7, wherein a diffusion layer 4 is formed between the input charge control region 3 and the sensing region 5 of the substrate 10, and dopants for producing charges having the same polarity as the charges supplied from the charge input region 2 are diffused in the diffusion layer 4.