Yttrium Oxyfluoride Thermal Spray Composition for Stable F/Y Ratio
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Solution Overview
Problem
Existing thermal spray materials struggle to form a thermal sprayed film with a desired composition of yttrium oxyfluoride, particularly a desired molar ratio of F and Y (F/Y), due to compositional variation during thermal spraying in air, which affects corrosion resistance and stability in different etching environments.
Innovation Solution
A thermal spray material comprising composite particles of yttrium oxide and ammonium yttrium fluoride, specifically NH4Y2F7, is used to form a thermal sprayed film with a controlled F/Y ratio by minimizing fluorine loss during thermal spraying in air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an yttrium oxyfluoride thermal spray material is used, then corrosion resistance to plasma is improved, but compositional variation occurs during thermal spraying in air causing unstable F/Y ratio
Solution Approach 1:
The patent uses a composite material system consisting of yttrium oxide particles and ammonium yttrium fluoride particles. The yttrium oxide provides structural stability and corrosion resistance, while the ammonium yttrium fluoride serves as a fluorine source that decomposes during thermal spraying to form yttrium oxyfluoride. This composite approach allows the final coating composition to be controlled by the particle size ratio and mixing proportion, rather than being solely dependent on the raw material composition which would otherwise oxidize uncontrollably in air during spraying.
Solution Approach 2:
The patent controls the composition of the thermal sprayed film by changing parameters of the thermal spray material: specifically, the particle size distribution (D10, D50, D90 values) and mixing ratio of yttrium oxide to ammonium yttrium fluoride. By adjusting these parameters, the desired F/Y ratio can be achieved in the final coating even when spraying in air, because the decomposition behavior and oxidation resistance are influenced by particle size and composition ratio.
2Manufacturing precision
If the thermal spray material composition is adjusted to achieve desired F/Y ratio, then compositional control is improved, but fluorine loss during thermal spraying increases
Solution Approach 1:
The patent performs preliminary action by pre-mixing yttrium oxide and ammonium yttrium fluoride in specific proportions and particle size distributions before thermal spraying. The ammonium yttrium fluoride acts as a fluorine reservoir that decomposes at thermal spraying temperatures to release fluorine in situ, compensating for fluorine loss that would otherwise occur. This preliminary preparation ensures that the desired F/Y ratio is achieved in the final coating without needing to overcompensate for anticipated fluorine loss in the raw material composition.
Solution Approach 2:
Ammonium yttrium fluoride serves as an intermediary substance that facilitates fluorine transfer. Instead of directly using yttrium oxyfluoride or yttrium fluoride which would lose fluorine during thermal spraying, the patent uses ammonium yttrium fluoride as a stable intermediate that decomposes to release fluorine bound to yttrium in the final coating. This intermediary approach allows precise control of fluorine content while minimizing fluorine loss during the thermal spraying process.
3Adaptability or versatility
If a thermal sprayed film with controlled composition is formed, then adaptability to different etching environments is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by using particles with different functions in a composite mixture: yttrium oxide particles provide structural integrity and oxidation resistance, while ammonium yttrium fluoride particles provide fluorine source for forming yttrium oxyfluoride. Each component has a specific role and property optimized for its function. The final coating composition can be tailored for different etching environments (fluorine-rich or oxygen-rich plasma) by adjusting the mixing ratio and particle size distribution of the composite material, without complicating the manufacturing process.
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 thermal sprayed film achieves a desired composition and enhanced corrosion resistance, adapting to various etching environments by maintaining a stable F/Y ratio, thus improving the stability and effectiveness of the etching process.
Implementation Method 1
thermal spraying in air with using a thermal spray material
Implementation Method 2
composite particles containing an yttrium oxide and a double salt of ammonium yttrium fluoride
Data Source
AI summary
This thermal spray material including composite particles containing an yttrium oxide and an ammonium yttrium fluoride complex salt is used to form a thermal spray film comprising yttrium oxyfluoride formed by thermal-spraying in the air. When the thermal spray film is formed through thermal-spraying in the air by using the thermal spray material of the present invention, the loss of fluorine from the thermal spraying material during thermal-spraying is reduced, and a thermal spray film containing yttrium oxyfluoride can be formed by controlling a composition, so that a thermal spray film having a desired composition, particularly a desired F/Y, can be easily formed.