Metal-2D Material Junction Structure for Low-Resistance Semiconductor Contacts

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Solution Overview

Problem

Semiconductor devices face challenges in reducing contact resistance at metal-semiconductor junctions due to the Schottky energy barrier, which existing methods have not adequately addressed.

Innovation Solution

Incorporating a two-dimensional (2D) material layer, such as intrinsic graphene or nanocrystalline graphene, between the metal and semiconductor layers to reduce contact resistance by eliminating interfacial layers and pinning phenomena, with the 2D material layer directly grown on a germanium-based second semiconductor layer to prevent the formation of unstable oxide layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a metal layer is directly contacted with a semiconductor layer to exchange electrical signals, then wiring conductivity is improved, but contact resistance increases due to Schottky energy barrier

Engineering Contradiction:
Improvecontact resistanceVSAvoidjunction structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

A two-dimensional material layer is introduced as an intermediary between the metal layer and the semiconductor layer. This 2D material layer serves as a mediator that reduces the Schottky energy barrier at the metal-semiconductor junction, thereby reducing contact resistance while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite structure consisting of metal layer + two-dimensional material layer + semiconductor layer. This composite junction structure combines the advantages of metal (high conductivity) and semiconductor (controlled electrical properties) while the 2D material layer provides optimal interface properties, achieving low contact resistance through material composition rather than structural complexity.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If various methods are used to lower Schottky energy barrier between semiconductor and metal, then contact resistance is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvecontact resistanceVSAvoidfabrication process
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter by selecting specific two-dimensional materials (such as graphene, transition metal dichalcogenides) with appropriate work functions and electronic properties. By adjusting the material composition and crystal structure of the 2D layer, the Schottky barrier height is optimized, achieving low contact resistance through material selection rather than complex fabrication processes.

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

This configuration significantly decreases contact resistance by eliminating interfacial layers and enhancing electrical conductivity, as demonstrated by increased current characteristics in voltage-current measurements.

Implementation Method 1

contact resistance is generated due to the semiconductor/metal heterojunction. In order to reduce the contact resistance, various methods for lowering a Schottky energy barrier between a semiconductor and a metal have been proposed.

Methodology Applied
Scientific EffectSchottky energy barrier: Electrical Resistance

Implementation Method 2

a 2D material layer having a 2D crystal structure between a metal layer and a semiconductor layer

Methodology Applied
Scientific Effect2D crystal structure:

Data Source

PatentEP4270486A1Semiconductor device including metal-2 dimensional material-semiconductor junction
Publication Date: 2023.11.01 SAMSUNG ELECTRONICS CO LTD
  • EP4270486A1 patent drawingFigure 1
  • EP4270486A1 patent drawingFigure 2
  • EP4270486A1 patent drawingFigure 3~4

AI summary

A semiconductor device may include a first semiconductor layer including a first semiconductor material; a metal layer facing the first semiconductor layer and having conductivity; a 2D material layer between the first semiconductor layer and the metal layer; and a second semiconductor layer between the first semiconductor layer and the 2D material layer. The second semiconductor layer may include a second semiconductor material different from the first semiconductor material. The second semiconductor layer and the 2D material layer may be in direct contact with each other. The second semiconductor material may include germanium.