Al Conductive Line Stack for Residue-Free Display Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The generation of excessive residue during the etching process of conductive lines in display devices, particularly when using aluminum (Al) materials, which hinders the production of high-resolution displays with low resistance conductive lines.
Innovation Solution
A conductive line structure comprising a first layer of aluminum or aluminum alloy, a second layer of refractory metal nitride, and a third layer with a multilayer structure of refractory metals, including titanium, to prevent residue formation during etching, achieved through discontinuous deposition techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capping layer including titanium is formed on the aluminum conductive line to prevent hillock generation, then hillock formation is prevented, but excessive residue is generated during the etching process
Solution Approach 1:
The capping layer is divided into multiple sub-layers (first capping sub-layer, second capping sub-layer, and third capping sub-layer) with different materials and functions. The first sub-layer (titanium) prevents hillock formation, the second sub-layer (titanium nitride) provides etch selectivity to reduce residue, and the third sub-layer (titanium oxide) offers additional protection and adhesion. This segmentation resolves the contradiction by distributing functions across multiple layers rather than relying on a single thick layer.
Solution Approach 2:
The capping layer uses a composite structure combining different refractory materials (titanium, titanium nitride, and titanium oxide) with complementary properties. Each material contributes specific characteristics: titanium for hillock prevention, titanium nitride for etch resistance, and titanium oxide for adhesion and protection. This composite approach allows simultaneous achievement of hillock prevention and residue reduction.
2Reliability
If the thickness of the capping layer is increased to improve hillock prevention, then hillock formation is reduced, but excessive residue is generated during etching
Solution Approach 1:
Instead of using a single thick capping layer, the structure segments the total thickness into multiple thinner sub-layers with specific functions. The first sub-layer (50-150 nm titanium) provides sufficient hillock prevention, while the second sub-layer (50-150 nm titanium nitride) and third sub-layer (10-50 nm titanium oxide) control etching behavior and reduce residue generation through their material properties rather than relying on increased total thickness.
Solution Approach 2:
The invention changes the material composition parameters of each sub-layer to optimize both hillock prevention and etching performance. By selecting specific materials with different etch rates and properties (titanium, titanium nitride, titanium oxide), the structure achieves effective hillock prevention at controlled thicknesses while maintaining etching precision through material selection rather than thickness alone.
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 structure effectively reduces residue generation during etching, enabling the production of high-resolution display devices with improved conductive line performance and reduced hillock formation.
Implementation Method 1
a third layer disposed on the second layer, the third layer including a refractory metal having a multilayer structure including a plurality of stacked sub-layers
Data Source
AI summary
A conductive line for a display device may include a first layer including aluminum (Al) or an aluminum alloy, a second layer disposed on the first layer, the second layer including titanium nitride (TiNx), and a third layer disposed on the second layer, the third layer including titanium (Ti) and having a multilayer structure including a plurality of stacked sub-layers.