Deposition Apparatus External Chamber Parasitic Plasma Control
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Solution Overview
Problem
Conventional deposition apparatuses with a dual reactor structure suffer from parasitic plasma generation in the external chamber due to potential differences between the reactor wall and ground, affecting the plasma process within the reactor, especially when high RF power is applied.
Innovation Solution
A deposition apparatus and method that maintains a lower pressure in the external chamber than the reaction chamber by supplying an inert charge gas, such as nitrogen, to prevent parasitic plasma formation and ensure plasma generation only within the reactor, thereby stabilizing the process and preventing charge gas backflow during substrate loading/unloading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high RF power is supplied to the internal reactor to generate plasma, then plasma generation is improved, but parasitic plasma is generated in the external chamber
Solution Approach 1:
A potential equalization structure (intermediary element) is introduced between the internal reactor and external chamber to equalize potentials. This mediator prevents potential difference-driven parasitic plasma generation while allowing the high RF power to continue generating useful plasma in the reaction space.
Solution Approach 2:
The potential parameter of the reactor wall is changed from being floating at a different potential to being equalized with the ground potential through the potential equalization structure. This parameter change eliminates the driving force for parasitic plasma generation while maintaining high RF power operation.
2Adaptability or versatility
If plasma is generated in both the external chamber and reaction space, then plasma coverage is improved, but process stability deteriorates due to plasma influence on the process
Solution Approach 1:
The harmful parasitic plasma generation in the external chamber is extracted and eliminated by introducing the potential equalization structure. This allows the system to maintain plasma generation in the reaction space while removing the destabilizing plasma presence from the external chamber.
3Device complexity
If the external chamber is left at atmospheric pressure, then structure simplicity is maintained, but charge gas backflow occurs during substrate loading/unloading
Solution Approach 1:
The pressure parameter of the external chamber is changed from atmospheric pressure to a controlled lower pressure by introducing a pressure control valve. This parameter change prevents charge gas backflow during substrate handling while adding minimal structural complexity through a single valve component.
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
Effectively prevents parasitic plasma generation in the external chamber even at high RF power levels, maintaining process stability and ensuring that the charge gas does not flow backward into the reaction chamber, thus enhancing the deposition process.
Implementation Method 1
Pressure that is maintained by the charge gas that is supplied to the external chamber may be lower than pressure within the reaction chamber
Implementation Method 2
when plasma power is supplied to a reaction space, plasma is formed within the reaction space
Data Source
AI summary
A deposition apparatus and a method of depositing a thin film using the same are provided. By maintaining pressure of an external chamber between a reaction space and an outer wall slightly lower than pressure of the reaction space by supplying a charge gas to an external chamber of a space between the reaction space and an outer wall, parasitic plasma can be prevented from being generated within the external chamber. When loading or unloading a substrate, a charge gas of the external chamber can be prevented from flowing backward to the reaction space, and by supplying nitrogen gas as a charge gas, even if high plasma power is supplied, parasitic plasma can be effectively prevented from being generated in the external chamber.