Plasma Chamber Cleaning with Lifted Edge Ring Positioning
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Solution Overview
Problem
In plasma processing apparatuses, deposits such as CF-based polymers accumulate on the substrate placement surface, edge rings, and their lower surfaces, leading to poor substrate attraction and increased damage during extended cleaning processes, making it difficult to remove these deposits effectively without damaging the stage.
Innovation Solution
The apparatus includes a stage with a first placement surface for substrates and a second placement surface for edge rings, with elevating mechanisms to separate and position the edge rings, allowing for controlled plasma generation to concentrate cleaning efforts on the edge rings' lower surfaces and peripheries, thereby efficiently removing deposits while minimizing damage to the stage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If extended plasma cleaning is performed to remove deposits, then cleaning effectiveness is improved, but damage to the stage increases
Solution Approach 1:
The patent applies local quality by positioning the edge ring at a specific height above the stage surface, creating a non-uniform plasma distribution where plasma density is concentrated in the region between the edge ring and stage. This localized plasma concentration enables effective cleaning of deposits on the stage outer periphery and edge ring inner periphery without requiring extended cleaning that would damage the entire stage surface.
2Reliability
If plasma cleaning is performed on the stage, then deposits are removed, but the cleaning time increases
Solution Approach 1:
By controlling the edge ring height to create concentrated plasma distribution in specific regions, the cleaning process targets only the areas with deposits (stage outer periphery and edge ring inner periphery) rather than uniformly cleaning the entire stage. This localized approach significantly reduces cleaning time while maintaining effective deposit removal.
Solution Approach 2:
The patent employs partial action by generating plasma only in the necessary regions between the edge ring and stage surface, rather than applying plasma uniformly across the entire stage. This partial plasma generation achieves sufficient cleaning effectiveness for the critical areas without the time penalty of comprehensive stage cleaning.
3Productivity
If the edge ring is placed close to the stage, then cleaning efficiency is improved, but the risk of plasma damage to the stage increases
Solution Approach 1:
The patent optimizes the edge ring height parameter to a specific range (1mm to 5mm above the stage surface). This parameter adjustment creates an optimal balance where plasma is sufficiently concentrated for efficient cleaning while maintaining safe distance to prevent plasma damage to the stage. The specific height parameter controls both plasma density and damage risk simultaneously.
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 method allows for the reliable removal of deposits on the outer periphery of the stage, inner periphery of the edge ring, and lower surface of the edge ring in a short time, while protecting the stage from excessive plasma exposure, thus extending its lifespan.
Implementation Method 1
plasma is generated by supplying radio-frequency power from the radio-frequency power source to the stage
Data Source
AI summary
A plasma processing apparatus includes a processing container, a stage provided inside the processing container, the stage having a substrate placement surface and a ring-member placement surface surrounding an outer periphery of the substrate placement surface, a ring placed on the ring-member placement surface, a first elevating mechanism including first lift pins configured to support a substrate, a second elevating mechanism including second lift pins configured to support the ring, and a controller. The controller is configured to execute an operation (a) of cleaning an interior of the processing container using plasma in a state where a dummy substrate is supported on the first lift pins by controlling the first elevating mechanism, and an operation (b) of cleaning the interior of the processing container using the plasma in a state where the ring is supported on the second lift pins by controlling the second elevating mechanism.