Plasma Chamber Cleaning with Protective Film for Uniform Etch Removal
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Solution Overview
Problem
Current plasma processing technologies face challenges in achieving uniform cleaning within processing containers, leading to potential over-cleaning and increased costs due to frequent replacement of containers and particle generation.
Innovation Solution
A cleaning method that involves forming a protective film in the plasma generation region using SiN4 and NH3 gases, followed by a cleaning step with NF3 gas to uniformly clean both the plasma generation and diffusion regions, preventing over-cleaning and reducing container replacement frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma processing is performed in a processing container, then substrate processing is achieved, but cleaning uniformity within the container deteriorates leading to over-cleaning and particle generation
Solution Approach 1:
The patent applies local quality by forming a protective film specifically in the plasma generation region (upper portion of the container) where cleaning intensity is highest. This allows different regions of the container to have different protective characteristics - the plasma generation region has enhanced protection while the diffusion region maintains normal cleaning. This resolves the contradiction by enabling uniform cleaning across the entire container without over-cleaning any specific area.
Solution Approach 2:
The protective film is formed in advance before the cleaning process begins. This preliminary action prepares the container surface to resist excessive cleaning effects during the subsequent plasma cleaning operation. By pre-establishing the protective film in the plasma generation region, the system prevents over-cleaning and particle generation before they can occur, rather than attempting to correct them after the fact.
2Reliability
If cleaning is performed to remove deposits, then processing container cleanliness is improved, but container replacement frequency increases due to over-cleaning damage
Solution Approach 1:
By applying protective film selectively to the plasma generation region where cleaning is most intense, the patent protects the container wall in the area most susceptible to over-cleaning damage. This local protection strategy allows aggressive cleaning to be performed effectively while preserving the container's structural integrity and extending its service life, thus resolving the contradiction between maintaining cleanliness and preserving container durability.
Solution Approach 2:
The patent converts the potentially harmful effect of intense plasma cleaning in the generation region into a beneficial outcome by using the same plasma process to deposit a protective film that prevents damage. The intense plasma that would normally cause over-cleaning and damage is instead used to create a protective layer, transforming the harmful effect into a protective mechanism that extends container life while maintaining cleaning effectiveness.
3Productivity
If intensive cleaning is applied to the plasma generation region, then cleaning effectiveness is improved, but particle generation increases
Solution Approach 1:
The patent applies different cleaning protection strategies to different regions: the plasma generation region receives intensive cleaning enhanced by the protective film, while the diffusion region undergoes gentler cleaning. This localized approach allows effective removal of deposits in the generation region without generating particles, because the protective film prevents the intense plasma from damaging the container wall and generating particles.
Solution Approach 2:
The protective film acts as an intermediary layer between the intense plasma cleaning process and the container wall. It mediates the interaction by absorbing the intense cleaning action in the plasma generation region, allowing effective cleaning to occur while preventing the plasma from directly damaging the container wall and generating particles. The film serves as a buffer that enables intensive cleaning without the harmful side effects.
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 improves cleaning uniformity within the processing container, reduces particle generation, and decreases the frequency of container replacement, thereby lowering operational costs.
Implementation Method 1
generating plasma while supplying a film-forming gas into a processing container
Data Source
AI summary
The cleaning method according to an embodiment of the present invention is for cleaning a plasma processing apparatus that performs a plasma processing on a substrate. This cleaning method includes: forming a protective film; and cleaning. The forming the protective film involves forming the protective film in a plasma generation region by generating plasma while supplying a film-forming gas into a processing container in which a processing space including the plasma generation region and a diffusion region is formed. The cleaning involves cleaning an interior of the processing container in which the protective film has been formed by generating plasma while supplying a cleaning gas into the processing container.