Copper-Titanium Etchant Profile Control for Thick Wiring
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Solution Overview
Problem
The challenge in manufacturing thin film transistor array panels is the deterioration of thick copper wiring profiles during the etching process, which affects the performance and reliability of display devices.
Innovation Solution
The use of a copper-titanium etchant or copper etchant, comprising persulfate, inorganic acids, cyclic amines, organic acids, p-toluenesulfonic acid, and water, which allows for improved etching characteristics and profile control of copper and titanium layers, enabling the formation of metal wiring with desirable dimensions and low defectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of copper wiring is increased to handle higher current in larger display devices, then the electrical conductivity and current carrying capacity are improved, but the profile deterioration during etching process worsens
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition and concentration ratios of etchant components (persulfate, cyclic amine compound, organic acid, inorganic acid) to optimize the etching process for thick copper layers. By adjusting these chemical parameters, the etchant achieves selective removal of copper while preserving the profile integrity of thick wiring structures, thereby resolving the contradiction between improved electrical conductivity and maintained manufacturing precision.
Solution Approach 2:
The patent employs a composite etchant formulation combining multiple chemical agents (persulfate as primary etchant, cyclic amine compound for profile control, organic acid for buffering, and inorganic acid for selective etching) to achieve simultaneous copper removal and profile preservation. This composite approach allows the etchant to address multiple requirements (etching speed, profile control, selectivity) that cannot be met by a single chemical component, thus resolving the technical contradiction.
2Ease of manufacture
If conventional etchants are used for thick copper layers, then the etching process is simple, but the etching characteristics and profile control deteriorate
Solution Approach 1:
The patent uses a composite etchant system combining persulfate, cyclic amine compounds, organic acids, and inorganic acids to achieve superior etching characteristics for thick copper layers. This multi-component formulation provides synergistic effects that improve profile control and etching uniformity while maintaining practical manufacturing simplicity through a single-bath process, thus resolving the contradiction between ease of manufacture and manufacturing precision.
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 etchants effectively improve the etching characteristics of thick copper layers, maintaining a suitable taper angle and reducing defects, thereby enhancing the manufacturing process and device performance.
Implementation Method 1
an etchant including: 5 to 20 wt % of persulfate
Implementation Method 2
0.3 to 5 wt % of a cyclic amine compound
Data Source
AI summary
An etchant includes: 5 to 20 wt % of persulfate, 1 to 10 wt % of at least one compound of an inorganic acid, an inorganic acid salt, or a mixture thereof, 0.3 to 5 wt % of a cyclic amine compound, 1 to 10 wt % of at least one compound of an organic acid, an organic acid salt, or a mixture thereof, 0.1 to 5 wt % of p-toluenesulfonic acid, and water, based on the total weight of the etchant. A copper-titanium etchant further includes 0.01 to 2 wt % of a fluoride-containing compound. A method of forming a display device using the etchant, and a display device, are also disclosed.