Dual-Gate Ferroelectric Memory for Linear Conductance

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Solution Overview

Problem

Current neuromorphic processors face challenges in achieving linear response characteristics for pattern recognition, which is crucial for efficient neural network operations, due to non-linear changes in conductance caused by gate voltages.

Innovation Solution

A ferroelectric memory device is designed with a channel layer, two gate electrodes, and a ferroelectric layer, where different voltages can be independently applied to each gate electrode, improving the linearity of conductance changes by combining pulse and DC voltages, and optimizing the materials and structures for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single gate electrode is used in a memory cell, then the device structure is simple, but the conductance change response to gate voltage is non-linear

Engineering Contradiction:
Improvegate electrode structureVSAvoidlinearity of conductance response
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The single gate electrode is divided into two separate gate electrodes (first gate electrode and second gate electrode) that can be independently controlled. This segmentation allows independent adjustment of voltages applied to each gate, enabling linearization of the overall conductance response through coordinated voltage control while maintaining relatively simple individual gate structures

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If different voltages are applied to two gate electrodes to improve linearity, then the conductance response becomes linear, but the device operation becomes more complex

Engineering Contradiction:
Improvelinearity of conductance responseVSAvoidvoltage control complexity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The voltage control system applies periodic pulse voltages to the first gate electrode and complementary DC or pulse voltages to the second gate electrode. This periodic action pattern simplifies the control logic by establishing a predictable voltage application sequence, making it easier to manage the dual-gate system while achieving linear conductance modulation

Inventive Principle:
Principle #19Periodic action

3Device complexity

If conventional memory structures are used, then the device structure is simple, but power consumption is high and area is large

Engineering Contradiction:
Improvememory cell structureVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The memory cell utilizes ferroelectric material properties and dual-gate voltage control to dynamically adjust conductance states. By changing the voltage parameters applied to the two gates independently, the device achieves better area efficiency and power consumption characteristics while maintaining non-volatile memory functionality, overcoming the limitations of conventional single-gate structures

Inventive Principle:
Principle #35Parameter changes

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 ferroelectric memory device achieves improved linearity in conductance changes, enhancing pattern recognition rates and reducing power consumption, making it suitable for neuromorphic processors and neural network operations.

Implementation Method 1

a ferroelectric layer between the channel layer and the first gate electrode and the ferroelectric layer may be between the channel layer and the second gate electrode

Methodology Applied
Scientific EffectFerroelectric effect:

Data Source

PatentEP4184511A1Ferroelectric memory device and electronic device including the same
Publication Date: 2023.05.24 SAMSUNG ELECTRONICS CO LTD
  • EP4184511A1 patent drawingFigure 1~2
  • EP4184511A1 patent drawingFigure 3A~3B
  • EP4184511A1 patent drawingFigure 3C

AI summary

A ferroelectric memory device may include a source, a drain, a channel layer between the source and the drain and connected to the source and the drain, a first gate electrode and a second gate electrode located on the channel layer to be spaced apart from each other, and a ferroelectric layer between the channel layer and the first gate electrode and between the channel layer and the second gate electrode. Different voltages may be applied to the first gate electrode and the second gate electrode.