Single-Transistor DRAM Memory Element With Segmented Body

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing single-transistor DRAM memory points face issues such as limited retention time, high power consumption, poor state differentiation, control complexity, and manufacturing difficulties due to the need for simultaneous presence of electrons and holes in the transistor body, which are not adequately addressed by previous capacitorless designs.

Innovation Solution

A single-transistor DRAM memory point is designed with a body region divided into two distinct regions by an insulating layer, where the channel region closest to the gate has a thickness of 5 to 50 nm, and a second gate is optionally provided under the body region, allowing for efficient charge storage and differentiation between states through precise voltage control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the transistor body thickness is reduced for miniaturization, then the device size is reduced, but the ability to maintain simultaneous presence of electrons and holes deteriorates

Engineering Contradiction:
Improvetransistor sizeVSAvoidcharge storage capability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The transistor body is segmented into two distinct regions separated by an insulating layer: a first region for storing electrons and a second region for storing holes. This segmentation allows each region to independently maintain its charge carriers even when the overall transistor thickness is reduced, resolving the contradiction between miniaturization and charge storage capability.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single transistor without capacitor is used, then the device complexity is reduced, but the retention time is limited

Engineering Contradiction:
Improvememory structure complexityVSAvoidretention time
Core Design Contradiction:
Device complexityVSDuration of action of moving object

Solution Approach 1:

The patent transitions from a planar single-region body to a vertically stacked multi-region structure with insulating layers. This dimensional organization creates electrically isolated zones within the transistor body, enabling long-term charge retention without requiring external capacitors, thus maintaining simplicity while extending retention time.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If the transistor body is made thinner, then the manufacturing precision is improved, but the control over charge distribution becomes more difficult

Engineering Contradiction:
Improvetransistor thickness controlVSAvoidcharge distribution control
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

Insulating layers are introduced as intermediary elements between the charge-storing regions. These intermediaries electrically isolate the first and second body regions, enabling independent control of electron and hole distributions even in thin transistors. The insulating layers act as mediators that maintain charge separation without requiring complex manufacturing processes.

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 design enhances retention time, reduces power consumption, simplifies control, and allows for thinner transistor bodies, effectively addressing the limitations of previous single-transistor memory points by enabling clear differentiation between storage states and improving manufacturing feasibility.

Implementation Method 1

the body region is divided in its thickness into two distinct regions separated by a portion of insulating layer extending parallel to the plane of the gate

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

the memorization corresponds to a storage of charges in the transistor

Methodology Applied
Scientific EffectCharge storage: Capacitance

Data Source

PatentEP2419902B1Ram memory element with one transistor
Publication Date: 2019.09.18 UNIV DE GRANADA
  • EP2419902B1 patent drawingFigure 1~4B
  • EP2419902B1 patent drawingFigure 5A~6D
  • EP2419902B1 patent drawingFigure 7A~9

AI summary

The invention relates to a memory element consisting of an MOS transistor having a drain (8), a source (7) and a body region covered by an insulated gate (12), wherein the thickness of the body region is divided into two distinct regions (13, 14) separated by a portion of an insulating layer (16) extending parallel to the plane of the gate.