Ge-Sb-S Self-Selecting Memory With OTS for Cross-Point Scaling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing memory devices with cross-point structures face challenges in minimizing memory cell size and preventing sneak currents due to the need for separate selectors and memories, limiting integration and efficiency.

Innovation Solution

A self-selecting memory (SSM) material comprising Ge, Sb, and S with ovonic threshold switching (OTS) characteristics, which changes threshold voltage based on voltage polarity and intensity, enabling a single device to function as both a memory and a selector, thereby reducing the need for separate components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate selectors and memory devices are used in cross-point structures, then sneak current prevention is achieved, but device complexity and integration density increase

Engineering Contradiction:
Improvesneak current preventionVSAvoidintegration density
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the selector and memory device into a single integrated structure where the chalcogenide material layer serves dual functions. The same material layer that stores data also provides the diode-like switching characteristics needed to prevent sneak currents, eliminating the need for separate selector components and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The chalcogenide material layer is designed to perform multiple functions simultaneously: it acts as both the memory storage medium and the selector component. This multi-functionality allows the device to prevent sneak currents while maintaining high integration density, as the same structural element fulfills both roles without requiring additional components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Area of moving object

If memory cell size is reduced in cross-point structures, then integration density improves, but sneak current control becomes more difficult

Engineering Contradiction:
Improvememory cell sizeVSAvoidsneak current control
Core Design Contradiction:
Area of moving objectVSReliability

Solution Approach 1:

By merging the selector and memory functions into a single material layer, the patent enables effective sneak current control even in miniaturized cells. The integrated structure ensures that the diode-like switching characteristics are maintained at the same location where data is stored, providing reliable sneak current prevention regardless of cell size reduction.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If threshold voltage stability is improved in SSM materials, then thermal stability increases, but manufacturing precision requirements increase

Engineering Contradiction:
Improvethreshold voltage stabilityVSAvoidmaterial composition control
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent employs composite chalcogenide materials with specific compositional ratios (such as Ge-Sb-S, Ge-Te-S, or In-Sb-Te) that inherently provide stable threshold voltage characteristics. The synergistic combination of different chalcogenide elements creates materials with improved thermal stability and controlled phase transition properties, reducing sensitivity to manufacturing variations while maintaining reliable switching behavior.

Inventive Principle:
Principle #40Composite materials

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 SSM material allows for miniaturized memory devices with improved thermal stability, increased memory capacity, and reduced sneak currents, facilitating higher integration and efficient operation.

Implementation Method 1

The memory layer may have ovonic threshold switching (OTS) characteristics, and may be configured to change a threshold voltage according to a polarity and an intensity of an applied voltage

Methodology Applied
Scientific EffectOvonic threshold switching (OTS):

Data Source

PatentEP4654196A1Self-selecting memory material, memory device, and electronic device including the memory device
Publication Date: 2025.11.26 SAMSUNG ELECTRONICS CO LTD
  • EP4654196A1 patent drawingFigure 1
  • EP4654196A1 patent drawingFigure 2
  • EP4654196A1 patent drawingFigure 3A

AI summary

A self-selecting memory (SSM) material, a memory device, and an electronic device including the memory device are provided. The SSM material may have ovonic threshold switching (OTS) characteristics, may be configured to change a threshold voltage according to a polarity and an intensity of an applied voltage, and may include Ge, Sb, and S.