Pressurized Etching Chamber to Stabilize Silicon Nitride Wet Etching
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Solution Overview
Problem
Current wet etching methods for silicon nitride films face challenges in maintaining etchant concentration due to vaporization, leading to inefficiencies and economic losses, and require improved selectivity over silicon oxide films.
Innovation Solution
An etching device and method that maintains a pressurized atmosphere within the etching chamber, utilizing an etchant supply unit, rinsing liquid supply unit, and cleaning liquid supply unit, with a pressurization maintaining unit to prevent etchant vaporization and control concentration, and includes a recovery line to recycle etchant, ensuring constant etchant concentration and enhanced selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If wet etching is performed without pressurization to maintain simple device structure, then device complexity is reduced, but etchant vaporization occurs causing concentration instability and economic loss
Solution Approach 1:
The patent applies pressurized atmosphere (inert environment) in the etching chamber to suppress etchant vaporization. By maintaining positive pressure, the etchant remains in liquid phase and prevents evaporation, thereby stabilizing etchant concentration throughout the etching process without requiring complex additional control systems.
Solution Approach 2:
The patent changes the pressure parameter of the etching chamber from atmospheric to pressurized state. This parameter change fundamentally alters the etchant's physical state and behavior, preventing vaporization and maintaining constant concentration. The system monitors and adjusts pressure to ensure optimal etching conditions are maintained.
2Stability of the object's composition
If large amounts of deionized water and etchant are added to maintain concentration during vaporization, then etchant concentration stability is improved, but economic loss increases
Solution Approach 1:
By maintaining a pressurized atmosphere in the etching chamber, the patent prevents etchant vaporization at the source. This eliminates the need to continuously replenish etchant to compensate for vaporization losses, thereby reducing both deionized water and etchant consumption while maintaining stable concentration.
Solution Approach 2:
The patent converts the potential harm of etchant vaporization into a benefit by using pressurization to control the vaporization process. The pressurized environment transforms what would be a loss mechanism into a controllable parameter, allowing precise management of etchant delivery and minimizing waste.
3Stability of the object's composition
If pressurization is applied to prevent etchant vaporization and maintain concentration, then etchant concentration stability is improved, but device complexity increases
Solution Approach 1:
The patent implements a pressurization system that maintains positive pressure in the etching chamber. This parameter change is achieved through integrated pressure control mechanisms that are part of the standard etching device architecture, allowing concentration stability without requiring entirely separate complex systems.
4Stability of the object's composition
If pressurized atmosphere is maintained during etching, then etchant vaporization is prevented and concentration is constant, but selectivity of silicon nitride etching improves requiring precise control
Solution Approach 1:
The pressurized atmosphere creates a controlled environment that enhances the chemical reaction between etchant and silicon nitride while suppressing unwanted side reactions. This improves selectivity by ensuring the etchant acts primarily on the target material rather than vaporizing or reacting with other components.
Solution Approach 2:
By controlling pressure as a key parameter, the patent optimizes the etching selectivity. The pressurized state modifies the etchant's reactivity and delivery characteristics, enabling precise control over etching rates and selectivity between different materials in the semiconductor structure.
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 approach prevents etchant vaporization, maintains constant concentration, reduces etchant consumption, and improves etching selectivity, thereby enhancing product yield and reducing costs.
Implementation Method 1
a first pressurization maintaining unit configured to maintain at least one of the etching chamber and the etchant supply unit in a pressurized atmosphere
Implementation Method 2
a desired target layer is selectively etched from an object (substrate, or the like) by a chemical reaction of an etchant
Data Source
AI summary
The present invention relates to an etching device and an etching method thereof, the etching device comprising: an etchant supply unit for supplying an etchant to an etching chamber, a rinsing liquid supply unit for supplying a rinsing liquid to the etching chamber; a cleaning liquid supply unit for supplying a cleaning liquid to the etching chamber; and a first pressurization maintaining unit for maintaining at least one of the etching chamber and the etchant supply unit in a pressurized atmosphere.