Low Temperature Fluoride Glaze for Plasma Etch Chamber Stability
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Solution Overview
Problem
Rare earth oxides used in chamber components transform into fluorides during processing, causing volume expansion and stress, leading to particle defects and difficulties in forming stable glazes due to high melting temperatures and instability at high temperatures.
Innovation Solution
A method involving mixing first and second fluorides with different melting temperatures to form a eutectic system, which is then melted and cooled to create a super-lattice with a lower melting temperature, allowing for the formation of a glaze or glass ceramic, or by exposing oxides to anhydrous hydrogen fluoride to convert them into fluorides and form a eutectic system for glaze formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rare earth oxides are used in chamber components, then erosion resistance is improved, but volume expansion and stress occur during transformation to fluorides, leading to particle defects
Solution Approach 1:
The patent applies preliminary action by pre-converting rare earth oxides to fluorides before chamber component assembly and operation. This prevents in-service transformation that causes volume expansion and particle shedding. The conversion is performed in a controlled environment using HF gas exposure, ensuring complete transformation before the component enters service, thereby eliminating the harmful particle defects during operation.
Solution Approach 2:
The patent changes the chemical state parameter of the rare earth material from oxide to fluoride form. This parameter change fundamentally alters the material's stability characteristics, preventing transformation during service. The fluoride form maintains dimensional stability and does not undergo further transformation under plasma etch conditions, thereby eliminating particle defect generation while preserving erosion resistance.
2Reliability
If YF3 is used as a coating for chamber components, then erosion resistance is improved, but the high melting temperature and instability at high temperatures make it difficult to form stable glazes
Solution Approach 1:
The patent employs composite materials by combining YF3 with other fluorides (such as AlF3, SiF4, or B2O3) to create a multi-component glaze system. This composite approach lowers the overall melting temperature of the coating mixture, enabling glaze formation at achievable temperatures. The composite glaze maintains the erosion resistance of YF3 while adding the benefits of lower processing temperature and improved stability, thereby resolving the manufacturing difficulty.
3Reliability
If rare earth oxides transform into fluorides during processing, then erosion resistance is maintained, but volume expansion causes added stress and particle shedding
Solution Approach 1:
The patent applies preliminary action by completing the oxide-to-fluoride transformation before component assembly and service operation. The conversion is performed in a controlled atmosphere using HF gas exposure at elevated temperatures, ensuring complete transformation to the stable fluoride form. This preliminary conversion eliminates subsequent volume expansion and stress development during chamber operation, preventing particle shedding while maintaining erosion resistance.
Solution Approach 2:
The patent changes the chemical composition parameter from oxide to fluoride state, which fundamentally alters the material's dimensional stability. The fluoride form has a stable crystal structure that does not undergo further transformation under plasma etch conditions. This parameter change eliminates the volume expansion phenomenon and associated internal stress, thereby preventing particle shedding while preserving the erosion resistance properties.
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 method results in a glaze or glass ceramic with improved stability and reduced porosity, providing enhanced erosion resistance in plasma etch chemistries and minimizing particle contamination, with a melting temperature significantly lower than individual fluorides, facilitating the formation of stable coatings for chamber components.
Implementation Method 1
The first fluoride and the second fluoride are melted by heating the mixture of the first fluoride and the second fluoride to a first temperature above at least the second melting temperature
Implementation Method 2
The mixture is cooled to form a material comprising a eutectic system having a super-lattice of the first fluoride and the second fluoride
Implementation Method 3
Oxygen molecules in the first oxide and the second oxide are replaced with fluorine molecules at a surface of the article or the coating
Data Source
AI summary
An article comprises a body having a coating. The coating comprising a eutectic system having a super-lattice of a first fluoride and a second fluoride. The coating includes a glaze on a surface of the coating, the glaze comprising the eutectic system having the super-lattice of the first fluoride and the second fluoride.