Noble Metal Contact Etching for Selective Tungsten Film Removal
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Solution Overview
Problem
Current substrate treatment methods for semiconductor devices face challenges in enhancing the etching rate of metal films without damaging the underlying patterns or structures, particularly when the metal films to be etched are the same as the conductor films, such as tungsten.
Innovation Solution
A substrate treatment apparatus utilizing a noble metal-containing member with a concave-convex surface, where the noble metal film is partially in contact with the metal film to be etched, and an alkaline oxidizing agent is used to promote galvanic corrosion, ensuring selective etching of the metal film while protecting the insulator and conductor films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional etching methods are used to remove metal films, then the metal film can be removed, but the etching rate is insufficient and the process is time-consuming
Solution Approach 1:
The patent changes the chemical parameters of the etching environment by introducing an alkaline oxidizing agent that creates a highly reactive chemical environment. This parameter change enables dramatically faster etching rates by transforming the etching mechanism from conventional chemical reactions to accelerated galvanic corrosion processes, directly resolving the contradiction between etching rate and time consumption
Solution Approach 2:
The noble metal-containing member acts as an intermediary element that facilitates galvanic corrosion. By introducing this intermediate substance that forms a galvanic cell with the metal film, the etching process is accelerated without requiring direct contact between the etchant and the entire metal film surface, thereby achieving high etching rates efficiently
2Productivity
If aggressive etching methods are used to increase etching rate, then the etching speed improves, but the underlying patterns and structures may be damaged
Solution Approach 1:
The patent applies local quality by making the noble metal contact only specific portions of the metal film surface through the concave-convex surface structure. This localized contact creates galvanic corrosion only at specific regions while leaving other areas protected, enabling selective etching that maintains pattern integrity while achieving high etching rates in targeted areas
Solution Approach 2:
The noble metal-containing member with concave-convex surface is designed as a consumable etching tool that can be easily replaced. This disposable approach allows aggressive local etching actions without concern for damage to precision tools, while the underlying patterns remain protected due to the controlled local galvanic corrosion mechanism
3Productivity
If the metal film is the same as the conductor film (e.g., tungsten), then selective etching becomes difficult, but the invention enables selective removal
Solution Approach 1:
The concave-convex surface structure creates local quality differences by providing noble metal contact only at specific convex portions while leaving concave portions exposed. This spatial differentiation enables selective etching of metal films even when they have the same material composition as conductor films, as the etching occurs only where galvanic corrosion is activated
Solution Approach 2:
The noble metal-containing member serves as an intermediary that introduces a different material property (noble metal) to the etching interface. This intermediary creates a galvanic potential difference that enables selective removal of the metal film based on its electrical connection to the noble metal, rather than relying solely on material composition differences
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 apparatus achieves a high etching rate of the metal film without damaging the pattern or structure, allowing for the selective removal of the metal film, even when it is the same as the conductor films, thereby enhancing the manufacturing efficiency of semiconductor devices.
Implementation Method 1
an alkaline oxidizing agent is used to promote galvanic corrosion, ensuring selective etching of the metal film while protecting the insulator and conductor films
Data Source
AI summary
According to an embodiment, a substrate treatment apparatus includes a hair member including a noble metal, and a liquid chemical supply member to supply a liquid chemical. While a tip part of the hair member is contact with a predetermined surface of a metal, the liquid chemical is supplied onto the surface of the metal, and the metal is removed with etching.