Titanium Copper Etchant Profile Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The etching of titanium/copper multilayered films presents challenges due to poor etching profiles and difficulties in subsequent processes, particularly in achieving desired etch profiles and controlling etching speeds.
Innovation Solution
An etchant comprising persulfate, fluorine compounds, inorganic acids, cyclic amines, chlorine compounds, copper salts, and organic acids is used to effectively etch titanium/copper films, optimizing etching profiles and speeds while preventing residual sand and substrate damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a titanium/copper double film is simultaneously etched, then the gate wire and data wire can be formed, but the etching profile becomes poor
Solution Approach 1:
The patent modifies the chemical composition parameters of the etchant by incorporating specific concentrations of persulfate (0.5-20 wt%), fluorine compounds (0.01-2 wt%), inorganic acids (1-10 wt%), and other additives. This parameter optimization enables selective etching of titanium and copper layers with distinct etching speeds, thereby achieving a desired etching profile with appropriate taper angles while maintaining ease of manufacture for gate and data wire formation
Solution Approach 2:
The etching process is segmented into selective etching of titanium layer followed by selective etching of copper layer. The patent uses a multi-component etchant that differentially attacks each metal layer at different rates, effectively separating the etching actions that were previously simultaneous and uncontrolled, thus improving etching profile precision
2Reliability
If copper is used for gate wire and data wire, then good electric conductivity and low resistance are achieved, but difficulties exist in photoresist coating and patterning
Solution Approach 1:
The patent employs a composite metal film structure of titanium and copper layers. The titanium layer provides adhesion and etchability for photoresist patterning, while the copper layer provides the desired electrical conductivity. This composite structure combines the advantages of both materials, enabling both good electrical performance and ease of photolithographic processing
3Productivity
If conventional etchants are used for titanium/copper film, then etching can be performed, but residual sand and substrate damage occur
Solution Approach 1:
The patent introduces fluorine compounds and organic additives as intermediary substances in the etchant formulation. These intermediaries facilitate the etching reaction while protecting the substrate from damage and preventing residual sand formation. The fluorine compounds specifically help in clean removal of metal layers without attacking the underlying substrate, acting as a protective mediator in the etching process
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 etchant provides excellent etching characteristics, including controlled etching speeds and profiles, reducing residual sand and substrate damage, and maintaining effectiveness over time, making it suitable for manufacturing display devices and other electronic components.
Implementation Method 1
The etchant comprises about 0.5 wt % to about 20 wt % of persulfate, about 1 wt % to about 10 wt % of inorganic acid
Implementation Method 2
The etchant comprises about 0.01 wt % to about 2 wt % of a fluorine compound, about 0.1 wt % to about 10 wt % of organic acid or organic acid salt
Data Source
AI summary
An etchant according to exemplary embodiments of the present invention includes about 0.5 wt % to about 20 wt % of persulfate, about 0.01 wt % to about 2 wt % of a fluorine compound, about 1 wt % to about 10 wt % of inorganic acid, about 0.5 wt % to about 5 wt % of a cyclic amine compound, about 0.1 wt % to about 5 wt % of a chlorine compound, about 0.05 wt % to about 3 wt % of copper salt, about 0.1 wt % to about 10 wt % of organic acid or organic acid salt, and water.