Semiconductor Contact Structure Preventing Gold-Indium Reaction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electrical contact structures for semiconductor components, particularly those using gold in contact with transparent conductive oxides, can lead to conductivity reduction and 'efflorescence' due to reactions between gold and indium, resulting in increased operating voltage and potential damage.

Innovation Solution

An electrical contact structure featuring a transparent electrically conductive contact layer, a first metallic contact layer of aluminium, a second metallic contact layer of gold separated by a dielectric separating layer, and a barrier layer to prevent direct contact between gold and the transparent conductive oxide, thereby avoiding reactions and maintaining conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gold is used in direct contact with transparent conductive oxide containing indium, then good electrical contact is achieved, but reactions occur leading to conductivity reduction and efflorescence

Engineering Contradiction:

Improveelectrical contact reliabilityVSAvoidefflorescence and conductivity reduction

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A separating layer made of dielectric material (such as silicon dioxide, silicon nitride, or aluminium oxide) is introduced between the gold second metallic contact layer and the transparent conductive oxide containing indium. This intermediary layer prevents direct contact and chemical reactions between gold and indium, thereby avoiding efflorescence and conductivity reduction while maintaining reliable electrical contact through the first metallic contact layer (aluminium) that remains in direct contact with the transparent conductive oxide.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a separating layer is introduced to prevent gold-indium reactions, then conductivity is maintained, but device structure becomes more complex

Engineering Contradiction:

Improveconductivity stabilityVSAvoidcontact structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The contact structure is segmented into distinct functional layers: a first metallic contact layer (aluminium) that provides electrical contact to the transparent conductive oxide, and a second metallic contact layer (gold) that is separated from the transparent conductive oxide by a dielectric separating layer. This segmentation allows each layer to perform its specific function without causing harmful interactions, maintaining conductivity stability while using standard thin-film deposition techniques.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The separating layer serves multiple functions simultaneously: it acts as a physical barrier preventing gold-indium reactions, provides electrical insulation between the gold layer and the transparent conductive oxide, and can serve as part of the overall contact structure in standard thin-film deposition processes. This multi-functionality reduces the need for additional specialized components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 proposed contact structure prevents reactions between gold and indium-containing transparent conductive oxides, maintaining conductivity and preventing 'efflorescence', thus ensuring reliable and efficient electrical contact for semiconductor components.

Implementation Method 1

a separating layer, which is arranged between the transparent electrically conductive contact layer and the second metallic contact layer and which separates the second metallic contact layer from the transparent electrically conductive contact layer

Methodology Applied

Scientific EffectPhysical separation by dielectric layer: Dielectric

Implementation Method 2

a barrier layer between the first and second metallic contact layers, which barrier layer completely covers the first metallic contact layer and is covered, preferably completely, by the second metallic contact layer

Methodology Applied

Scientific EffectDiffusion barrier: Diffusion Barrier

Data Source

PatentUS9917229B2Electrical contact structure for a semiconductor component, and semiconductor component

Publication Date: 2018.03.13 AMS OSRAM INT GMBH

AI summary

An electrical contact structure (10) for a semiconductor component (100) is specified, comprising a transparent electrically conductive contact layer (1), on which a first metallic contact layer (2) is applied, a second metallic contact layer (3), which completely covers the first metallic contact layer (2), and a separating layer (4), which is arranged between the transparent electrically conductive contact layer (1) and the second metallic contact layer (3) and which separates the second metallic contact layer (3) from the transparent electrically conductive contact layer (1).Furthermore, a semiconductor component (100) comprising a contact structure (10) is specified.