Yttrium Oxide Plasma Coating With Low Porosity and Residual Stress
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Solution Overview
Problem
Existing films used in plasma processing devices face challenges such as high residual stress, porosity, and microcracks, which affect their corrosion resistance and reliability.
Innovation Solution
A film with yttrium oxide as the main component is developed, featuring a closed porosity of 0.2% or less and a full width at half maximum of 0.25° or less, achieved through a sputtering method that alternates metal yttrium film formation and oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a film is formed by the sol-gel method to improve corrosion resistance, then the full width at half maximum can be reduced, but the minimum value is limited to 0.3° and closed porosity remains high
Solution Approach 1:
The patent changes the deposition method from sol-gel to sputtering, and further optimizes by alternating between metal yttrium film formation and oxidation processes. This parameter change enables achieving a full width at half maximum of 0.25° or less while reducing closed porosity to 0.2% or less, overcoming the limitations of the sol-gel method
Solution Approach 2:
The patent employs periodic alternation between metal yttrium film formation and oxidation steps during the sputtering process. This periodic action allows the film to develop high crystallinity and density progressively, achieving both low full width at half maximum and low closed porosity that cannot be achieved by single-step methods
2Stress or pressure
If the thermal spraying method is used to reduce residual stress, then stress is reduced, but open porosity and closed porosity increase and microcracks form
Solution Approach 1:
The patent replaces the thermal spraying method (which uses high-velocity particle impact) with a sputtering method that uses physical vapor deposition. This substitution eliminates the mechanical impact that causes porosity and microcracks, while the alternating oxidation process ensures low residual stress through controlled crystallization
Solution Approach 2:
The patent utilizes phase transitions during the alternating oxidation process, where the deposited yttrium metal undergoes oxidation and crystallization in controlled steps. This controlled phase transition ensures proper stress management without creating the porosity and microcracks associated with thermal spraying
3Reliability
If the full width at half maximum is reduced below 0.3° to improve corrosion resistance, then corrosion resistance improves, but existing methods cannot achieve this level of precision
Solution Approach 1:
The patent segments the film formation process into multiple alternating steps of metal yttrium deposition and oxidation. This segmentation allows precise control over the film's crystalline structure, enabling achievement of full width at half maximum of 0.25° or less, which corresponds to superior corrosion resistance
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
The resulting film is dense, has small residual stress, and exhibits excellent corrosion resistance, leading to a more reliable plasma processing device with improved durability and productivity.
Implementation Method 1
a sputtering method that alternates metal yttrium film formation and oxidation
Implementation Method 2
a full width at half maximum of a diffraction peak on a (222) plane of yttrium oxide obtained by X-ray diffraction of the film
Implementation Method 3
a sputtering method that alternates metal yttrium film formation and oxidation
Data Source
AI summary
A member for use in a plasma processing device of the disclosure includes a base material and a film containing yttrium oxide as a main component on the base material. An area occupancy of closed pores of the film is 0.2 area % or less, and a full width at half maximum of a diffraction peak on a (222) plane of yttrium oxide obtained by X-ray diffraction of the film is 0.25° or less. A plasma processing device according to the disclosure includes the member for use in a plasma processing device.