Electro-Etching of Conductive Films for Area-Selective Substrate Isolation
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Solution Overview
Problem
Current wet chemical etching methods for semiconductor substrates lack the ability to perform area-selective treatment, leading to non-selective removal of materials and potential electrical shorts due to the inability to target specific surface areas, especially in complex structures like ridges and trenches, and require expensive, unstable chemical mixtures.
Innovation Solution
An electro-etching method and system that applies an electric potential to a substrate covered with an electrolyte, allowing for the selective removal of electrically conductive material by controlling the amount of electrons extracted and oxidized, enabling precise control over the etching process and avoiding the use of complex oxidizing media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet chemical etching is used to remove conductive material, then the material can be dissolved, but the etching is not area-selective and removes material uniformly across the entire substrate surface
Solution Approach 1:
The patent applies electro-etching to create local quality differences in the etching process. By applying electrical potential selectively to specific areas of the substrate through a conductive coating pattern, the etching action is concentrated only where electrical contact is made, enabling area-selective removal of conductive material while leaving other areas unaffected
Solution Approach 2:
The patent replaces the purely chemical wet etching mechanism with an electrochemical electro-etching mechanism. This substitution introduces electrical control to the etching process, allowing selective activation of etching in specific regions through electrical potential application, thereby achieving area-selectivity that cannot be obtained with chemical etching alone
2Productivity
If complex chemical mixtures containing oxidizers are used for high-speed etching, then etching speed increases, but the chemicals become expensive and unstable requiring frequent maintenance
Solution Approach 1:
The patent changes the fundamental parameter of the etching process from purely chemical reaction to electrochemical reaction. By applying electrical potential, the etching speed is controlled by electrical parameters rather than chemical concentration, enabling high-speed etching without requiring unstable oxidizing chemicals. The electrolyte solution becomes a stable conductive medium rather than a reactive oxidizer
Solution Approach 2:
The patent replaces expensive, unstable oxidizing chemicals with a simple, stable electrolyte solution that serves as a conductive medium. The electrolyte can be maintained at stable concentration and does not require frequent replacement or special handling, significantly reducing operational costs and improving process reliability
3Manufacturing precision
If chemical etching is used to remove conductive material between structures, then material dissolution occurs, but electrical shorts cannot be eliminated because all material layers are removed at the same rate
Solution Approach 1:
The patent creates local quality differences in material removal by applying electrical potential selectively. Areas with electrical contact undergo electro-etching and are selectively removed, while areas without electrical contact remain intact. This enables precise removal of conductive material between structures to eliminate electrical shorts while preserving the conductive material within structures that maintains electrical connectivity
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
Enables precise, area-selective etching with high speed and uniformity, reducing chemical costs and waste, improving process control, and eliminating electrical shorts by allowing targeted removal of conductive material between structures while preserving the material within them.
Implementation Method 1
an additional electron transfer process is required to oxidize the metallic surface atoms to corresponding metal-ions
Implementation Method 2
electro-etching the electrically conductive material by means of a combination of the electric potential and the electrolyte
Data Source
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AI summary
The application relates to an electro-etching method for an area-selective treatment of a substrate and an electro-etching system for an area-selective treatment of a substrate. The electro-etching method for an area-selective treatment of a substrate comprises: providing a substrate comprising a surface at least partially covered by at least one electrically conductive material and structures at least partially formed by the electrically conductive material, so that the structures are electrically connected by means of the electrically conductive material covering the surface, covering the substrate with an electrolyte, applying an electric potential to the substrate, electro-etching the electrically conductive material by means of a combination of the electric potential and the electrolyte, and continuing the electro-etching until the electrically conductive material at the surface is removed so that the structures are no longer electrically connected by means of the electrically conductive material covering the surface.