Multi-Layer Plasma Resistant Coating for High Aspect Ratio Parts
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Solution Overview
Problem
Existing protective coatings for semiconductor process chamber components with high-aspect ratio features, such as tubes and cylinders, are prone to failure due to particle contamination, metal contamination, and deviations in plasma composition, leading to inconsistent dielectric breakdown voltages and electrical impedance, especially when exposed to harsh plasma environments.
Innovation Solution
A multi-layer protective coating comprising an anodization layer with cracks and pores, a sealing layer of metal oxide deposited using atomic layer deposition (ALD) to seal the cracks and pores, and a top layer of metal oxide, ceramic, or rare earth oxide, which provides a uniform dielectric breakdown voltage and high electrical impedance, resistant to corrosion and erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer protective coating is deposited on high aspect ratio channels, then the coating provides some protection, but it is prone to failure due to particle contamination, metal contamination, and plasma composition deviations
Solution Approach 1:
The patent applies a multi-layer composite coating structure consisting of an anodization layer, a sealing layer, and a top layer. Each layer serves a specific function: the anodization layer provides corrosion resistance, the sealing layer seals pores and cracks to prevent contamination, and the top layer provides plasma resistance. This composite structure resolves the technical contradiction by combining multiple materials with complementary properties to achieve reliable protection against multiple harmful factors simultaneously.
Solution Approach 2:
The protective coating is segmented into three distinct functional layers. The anodization layer handles corrosion protection, the sealing layer addresses pore sealing and contamination prevention, and the top layer provides plasma resistance. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction by distributing protection responsibilities across multiple specialized layers rather than relying on a single-layer solution.
2Ease of manufacture
If non-line-of-sight deposition techniques are used to coat inner regions with high aspect ratios, then the coating can be deposited, but the coating quality is inconsistent and prone to failure
Solution Approach 1:
The multi-layer composite structure compensates for the limitations of non-line-of-sight deposition techniques. By using multiple layers with different functions, the system achieves consistent performance even when individual layers have minor variations in thickness or coverage. The sealing layer particularly helps by filling in defects and pores that may result from non-uniform deposition, thereby maintaining manufacturing precision despite the ease of manufacturing benefit from non-line-of-sight techniques.
Solution Approach 2:
Each layer in the composite structure provides localized quality enhancement. The anodization layer provides localized corrosion resistance, the sealing layer provides localized pore sealing, and the top layer provides localized plasma resistance. This local quality approach ensures that even if deposition is non-uniform, each region receives the specific protection it needs, resolving the contradiction between ease of manufacture and manufacturing precision.
3Reliability
If a protective coating is deposited on high aspect ratio channels, then the channels are protected, but the dielectric breakdown voltage varies significantly between parts
Solution Approach 1:
The multi-layer composite coating structure ensures consistent dielectric breakdown voltage across parts by providing multiple barriers with different properties. The anodization layer provides a consistent base layer, the sealing layer ensures uniform pore closure, and the top layer provides consistent plasma resistance. This composite approach reduces part-to-part variation in dielectric breakdown voltage by distributing the protective function across multiple consistent layers.
Solution Approach 2:
The patent controls the thickness and properties of each layer to achieve consistent dielectric breakdown voltage. By optimizing the parameters of each layer (anodization thickness, sealing layer thickness, top layer thickness), the system achieves uniform electrical properties across parts while maintaining effective protection. This parameter control resolves the contradiction by ensuring that the protective function is maintained while electrical consistency is improved.
4Reliability
If existing protective coatings are used in harsh plasma environments, then the channels are protected, but the coatings deteriorate due to erosion and corrosion
Solution Approach 1:
The multi-layer composite coating extends service life by providing multiple protective barriers. The anodization layer provides corrosion resistance, the sealing layer prevents contaminant ingress, and the top layer provides plasma erosion resistance. This composite structure resolves the contradiction by combining materials with different degradation resistance properties, ensuring that even if one layer degrades, the other layers continue to provide protection, thereby extending overall coating service life.
Solution Approach 2:
The multi-layer structure provides beforehand cushioning against degradation. Each layer acts as a buffer that can absorb damage before it reaches the underlying layers. The anodization layer provides initial corrosion protection, the sealing layer provides a buffer against contamination, and the top layer provides erosion resistance. This prior cushioning approach resolves the contradiction by ensuring that the coating system has built-in reserves of protection that extend service life under harsh plasma conditions.
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 multi-layer coating ensures consistent dielectric breakdown voltage and electrical impedance across parts, maintaining stability even at high temperatures and reducing plasma chemistry variations, thereby enhancing the reliability and consistency of plasma delivery systems.
Implementation Method 1
anodizing a surface of the one or more channels of a first article to form an anodization layer on the one or more channels
Implementation Method 2
depositing a sealing layer onto the anodization layer using an atomic layer deposition (ALD) process
Implementation Method 3
depositing a top layer onto the sealing layer using the ALD process
Data Source
AI summary
Disclosed herein is an article comprising one or more channels and a multi-layer protective coating on the one or more channels. The multi-layer protective coating includes an anodization layer comprising a plurality of cracks and a plurality of pores, a sealing layer on the anodization layer, and a top layer on the sealing layer. The sealing layer comprises a metal oxide, the seals the plurality of cracks and the plurality of pores, and has a porosity of approximately 0%. The top layer comprises a rare earth oxide, a rare earth fluoride, or a rare earth oxyfluoride, has a different material composition than the sealing layer, and has a porosity of approximately 0%.