Copper Conductor Array Substrate with Barrier Layer

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Solution Overview

Problem

In flat panel display devices, the increased length and decreased thickness of signal lines lead to high resistance and line defects, deteriorating image display quality due to chemical reactions with the substrate and insulating layers, and poor etching uniformity.

Innovation Solution

The use of a gate line and data line structures incorporating copper nitride layers and a triple-layered gate insulating structure with low and high density silicon nitride layers to reduce line resistance and defects, while simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the length of lines is increased and thickness is decreased to accommodate display device design requirements, then the resistance of lines is greatly increased, but this improves the display resolution and coverage

Engineering Contradiction:
Improvedisplay coverageVSAvoidline resistance
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent uses a composite material structure consisting of a copper layer combined with a molybdenum nitride barrier layer. The copper provides low resistance for signal transmission, while the molybdenum nitride layer prevents chemical reactions between copper and the insulating substrate. This composite structure resolves the contradiction by maintaining low line resistance while enabling extended line length for improved display coverage.

Inventive Principle:
Principle #40Composite materials

2Reliability

If copper conductors are used to decrease line resistance, then the resistance is reduced, but copper chemically reacts with insulating substrate and insulating layers causing line defects

Engineering Contradiction:
Improveline resistanceVSAvoidchemical reactions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a molybdenum nitride barrier layer as an intermediary between the copper conductor and the insulating substrate. This intermediate layer prevents direct chemical contact between copper and the substrate/insulating layers, thereby eliminating harmful chemical reactions and line defects while maintaining the low resistance benefit of copper conductors.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If metal layer etching is performed to form lines, then the lines are formed, but the etching uniformity of the metal layer is deteriorated, which deteriorates the etching profile of the lines

Engineering Contradiction:
Improveline formationVSAvoidetching uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The composite structure of copper combined with molybdenum nitride provides differential etching characteristics. The molybdenum nitride layer has different etching rates compared to copper, allowing for controlled etching processes that maintain uniformity. This composite material approach enables precise line formation with good etching profiles while facilitating manufacturing processes.

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

This approach effectively decreases line resistance and defects, improving image display quality and manufacturing efficiency by enhancing the adhesive strength and etching uniformity of the lines.

Implementation Method 1

the lines chemically react with an insulating substrate, an insulating layer, oxygen, etc., so that the resistance of the lines is greatly increased

Methodology Applied
Scientific EffectChemical reaction prevention: Diffusion Barrier

Implementation Method 2

enhancing the adhesive strength and etching uniformity of the lines

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP1881366B1Array substrate with copper conductors and method of manufacturing the same
Publication Date: 2010.09.15 SAMSUNG ELECTRONICS CO LTD
  • EP1881366B1 patent drawingFigure 1
  • EP1881366B1 patent drawingFigure 2
  • EP1881366B1 patent drawingFigure 3~4

AI summary

An array substrate includes a switching element (155), a signal transmission line (131), passivation layer (116) and a pixel electrode (112). The switching element is disposed on an insulating substrate (120). The signal transmission line is connected to the switching element and includes a barrier layer (131a), a conductive line (131b), and a copper nitride layer (131c). The barrier layer is disposed on the insulating substrate. The conductive line is disposed on the barrier layer and includes copper or copper alloy. The copper nitride layer covers the conductive line. The passivation layer covers the switching element and the signal transmission line and has a contact hole (151) through which a drain electrode (119) of the switching element is partially exposed. The pixel electrode (112) is disposed on the insulating substrate, and is connected to the drain electrode (119) of the switching element (155) through the contact hole (151).