Plasma Chamber Wall Deposition with Sample Table Film Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing plasma processing methods face challenges in preventing the formation of deposited films on mounting tables, which can lead to contamination of the transportation system when wafers are processed, as these films may adhere and detach during wafer handling, contaminating the system.
Innovation Solution
A plasma processing method involving steps to remove deposits in the processing chamber using SF6, O2, and Ar, followed by forming a deposited film on the chamber walls using CHF-based gases, and selectively removing deposits on the mounting table using O2 and Ar gases, while maintaining the film on the chamber walls, thereby preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deposited film is formed on the inner wall of the processing chamber to prevent foreign matter generation, then the protection of processing chamber components is improved, but the deposited film may adhere to the mounting table and contaminate the transportation system
Solution Approach 1:
The patent applies different gas compositions and plasma conditions to different spatial zones within the processing chamber. The mounting table region receives a gas mixture that prevents deposited film formation, while the chamber wall regions maintain conditions favorable for protective film deposition. This localized differentiation allows the same plasma processing system to simultaneously achieve both protection of chamber components and prevention of transportation system contamination.
Solution Approach 2:
The plasma processing method is divided into distinct temporal and spatial segments: a first plasma processing step that forms the protective deposited film on chamber walls, and a second plasma processing step that selectively removes films from the mounting table using oxygen-containing gas. This segmentation allows independent optimization of film formation and film removal processes, resolving the contradiction between protecting chamber components and preventing contamination.
2Reliability
If a dummy wafer is placed on the mounting table to prevent deposited film formation, then the mounting table is protected, but the deposited film on the dummy wafer may still detach and contaminate the transportation system
Solution Approach 1:
The patent extracts and removes the harmful deposited film from the dummy wafer surface through a dedicated oxygen plasma cleaning step. By applying oxygen-containing gas in a second plasma processing step, the deposited film that formed on the dummy wafer during the first step is selectively removed, preventing its subsequent detachment and contamination of the transportation system.
Solution Approach 2:
The patent converts the harmful effect of deposited film formation on the dummy wafer into a beneficial process by using the oxygen plasma step to intentionally form and then remove the film. The controlled formation of the film during the first step allows for its subsequent complete removal in the second step, ensuring no contamination occurs while still providing the benefit of film formation control.
3Manufacturing precision
If the processing time for plasma treatment is extended to ensure complete film removal, then the cleanliness of the mounting table is improved, but the production efficiency decreases
Solution Approach 1:
The patent optimizes the parameters of the second plasma processing step, including gas flow rates, power settings, and processing time, to achieve complete film removal in the shortest possible duration. By carefully controlling these parameters, the method ensures thorough cleaning of the mounting table while minimizing the time required, thus maintaining high production efficiency.
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 effectively suppresses contamination in the transportation system by ensuring the deposited film is formed only on the inner wall of the processing chamber, reducing the risk of foreign matter generation and allowing for the reuse of dummy wafers by selectively removing deposits from the mounting table.
Implementation Method 1
a first step of removing a residual film in the processing chamber by plasma of oxygen gas
Implementation Method 2
removing a residual film in the processing chamber by plasma of oxygen gas
Implementation Method 3
forming a deposited film on the inner wall of the processing chamber by using plasma of carbon fluoride gas
Implementation Method 4
forming a deposited film on the inner wall of the processing chamber by using plasma of carbon fluoride gas
Implementation Method 5
a third step of selectively removing the deposits on the sample table by using a mixed gas of oxygen (O2) gas and argon (Ar) gas
Implementation Method 6
selectively removing the deposits on the sample table by using a mixed gas of oxygen (O2) gas and argon (Ar) gas
Data Source
AI summary
Provided is a plasma processing method capable of suppressing the diffusion of contamination to a transportation system while forming a deposited film on the inner wall of a processing chamber. The plasma processing method, in which a sample placed on a sample table is plasma-processed in a processing chamber, includes: a first step of removing deposits in the processing chamber by using plasma; a second step of depositing the deposits in the processing chamber by using a mixed gas of hydrofluorocarbon gas and argon (Ar) gas after the first step; a third step of selectively removing the deposits on the sample table by using a mixed gas of oxygen (O2) gas and argon (Ar) gas after the second step; and a fourth step of plasma-processing a predetermined number of sheets of the sample after the third step.