Plated Intermediary Layer for LCD Al Line Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LCD devices face issues with corrosion of transparent conductive layers and increased contact resistance due to electrochemical reactions between aluminum interconnection lines and transparent conductive materials, which also lead to step coverage degradation and increased fabrication costs.
Innovation Solution
A method involving a patterned Al or Al alloy layer with a plated conductive material in contact holes, allowing the transparent conductive layer to be electrically connected without direct contact, thus preventing corrosion and reducing contact resistance, while eliminating the need for additional barrier layers and etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Al or Al alloy is used for interconnection lines to reduce resistance, then electrical resistance is reduced, but corrosion of transparent conductive material occurs due to electrochemical reaction
Solution Approach 1:
A plated conductive material layer is introduced as an intermediary between the Al interconnection line and the transparent conductive material. This intermediate layer prevents direct contact and electrochemical reactions, eliminating corrosion while maintaining electrical connectivity. The plated layer acts as a mediator that resolves the incompatibility between Al and transparent conductive materials.
2Device complexity
If Al layer and transparent conductive material are directly connected to reduce fabrication complexity, then device complexity is reduced, but contact resistance increases due to aluminum oxide formation
Solution Approach 1:
The plated conductive material serves as an intermediary layer that prevents oxygen from reaching the Al-transparent conductive material interface. By blocking oxygen diffusion, the plated layer prevents aluminum oxide formation and maintains low contact resistance, while the overall structure remains relatively simple.
3Manufacturing precision
If transparent conductive layer is patterned with etching solution to achieve precise patterning, then manufacturing precision is improved, but corrosion of transparent conductive layer occurs due to electrochemical reaction
Solution Approach 1:
The plated conductive material layer acts as a protective intermediary during the patterning process. It shields the transparent conductive material from direct exposure to etching and developing solutions, preventing electrochemical corrosion while allowing precise patterning to be achieved through standard photolithography processes.
4Reliability
If additional barrier layers are added to prevent corrosion and reduce contact resistance, then reliability is improved, but device complexity and fabrication cost increase
Solution Approach 1:
A single plated conductive material layer is used as an intermediary, providing both corrosion protection and low contact resistance in one layer. This approach is more efficient than adding multiple separate barrier layers, as the plated layer simultaneously addresses both reliability issues while maintaining relatively simple device structure.
Solution Approach 2:
The invention changes the material parameter by using plated conductive material with specific properties (high conductivity, corrosion resistance, oxygen barrier characteristics). This material selection optimizes both reliability parameters (corrosion resistance and contact resistance) without requiring complex multi-layer structures.
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 solution effectively prevents corrosion and contact resistance issues, improves step coverage, and reduces fabrication costs by eliminating the need for complex layer structures and specialized equipment, enhancing the reliability of gate and drain terminal sections.
Implementation Method 1
there is a problem that corrosion is likely to occur in the transparent conductive material due to electrochemical reaction caused by the developing or etching solution used for patterning the transparent conductive layer
Implementation Method 2
when an Al layer and a transparent conductive material are directly connected to each other, oxygen (O) atoms are likely to be drawn out of the transparent conductive material. In this case, an aluminum oxide (Al2O3) layer with an insulating property is formed at the interface between the Al layer and the transparent conductive material
Data Source
AI summary
A LCD device prevents corrosion of the transparent conductive layers and contact resistance increase without arising the step coverage degradation due to the thickness increase of the interconnection layer, the step coverage degradation due to the formation of undercut portions, and productivity reduction and fabrication cost increase. A first interconnection line comprising a patterned Al or Al alloy layer is disposed on or over an insulating plate. A first insulating layer is formed to cover the first interconnection line to have a contact hole exposing a part of the first interconnection line. A first conductive material made of a plated metal is in contact with the exposed part of the first interconnection line in the contact hole. A first transparent conductive layer is in contact with the first conductive material. The first transparent conductive layer is electrically connected to the first interconnection line by way of the first conductive material.