Multilayer ALD Coating for Plasma Chamber Component Durability
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges with the short lifetime of plasma processing chamber components due to material degradation, leading to particle contamination, impedance changes, and compromised etch and cleaning characteristics, as existing coatings are either not dense, conformal, or prone to cracking.
Innovation Solution
A rare earth metal-containing oxide coating structure is formed using atomic layer deposition (ALD), comprising a single amorphous layer with alternating crystalline layers, providing strong adhesion, ion bombardment resistance, and conformal coverage for complex surfaces, specifically using yttrium aluminate and yttria layers to enhance durability and plasma resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If existing coatings are applied to plasma processing chamber components, then component lifetime is extended, but the coatings are either not dense, not conformal, or prone to cracking
Solution Approach 1:
The coating is segmented into multiple thin alternating layers of amorphous and crystalline materials deposited via ALD, where each layer is nanometer-thin and uniformly distributed. This segmentation prevents cracking by distributing stress across multiple interfaces and ensures conformal coverage on complex geometries, resolving the reliability issue while maintaining extended component lifetime.
Solution Approach 2:
The invention uses a composite coating structure with alternating amorphous and crystalline layers of rare earth metal oxides. The amorphous layers provide flexibility and stress relief, while the crystalline layers provide density and chemical resistance. This composite structure eliminates the cracking problem of single-phase coatings while maintaining protective function, thus improving reliability without sacrificing component lifetime extension.
2Productivity
If plasma processing operations are performed with fluorine-based, chlorine-based, and hydrogen-based gases, then etching and cleaning operations are achieved, but material degradation occurs leading to particle contamination and impedance changes
Solution Approach 1:
The ALD coating acts as a sacrificial protective layer that resists degradation from aggressive plasma chemistries. While the coating itself is relatively thin and can be replaced, it protects the expensive chamber components (quartz, ceramics, metals) from degradation. The coating absorbs the harmful effects of fluorine-based, chlorine-based, and hydrogen-based plasmas, maintaining productivity while preventing material degradation and particle contamination.
Solution Approach 2:
The alternating amorphous and crystalline layers provide synergistic protection against different plasma chemistries. The crystalline layers offer dense barrier properties against chemical attack, while the amorphous layers provide stress relief and conformal coverage. This composite structure maintains etching and cleaning performance while significantly reducing material degradation compared to uncoated components.
3Ease of manufacture
If single-layer coatings are applied to provide protection, then manufacturing process is simple, but the coatings are not dense or conformal on complex surfaces
Solution Approach 1:
The coating process is segmented into multiple sequential ALD cycles depositing alternating amorphous and crystalline layers. Each cycle is simple and repeatable, maintaining ease of manufacture through automated ALD processing. The segmentation into thin layers ensures complete conformal coverage on complex surfaces and high density at each interface, resolving the manufacturing precision issue while keeping the overall process manageable through automation.
Solution Approach 2:
The invention transitions from single-layer to multi-layer deposition in the vertical dimension, creating nanometer-thin alternating layers. This dimensional approach allows each layer to be extremely thin and uniform, ensuring conformal coverage on complex geometries while maintaining process simplicity through repeated ALD cycles. The multi-layer structure achieves superior density and conformality without significantly increasing process complexity.
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 coating significantly prolongs the lifetime of plasma processing chamber components, reduces particle defects, maintains uniform plasma impedance, and ensures consistent etching and cleaning performance by resisting degradation from fluorine-based, chlorine-based, and hydrogen-based chemistries.
Implementation Method 1
A first coating including amorphous rare earth metal-containing oxide is formed by a first atomic layer deposition (ALD) process... A second coating including crystalline rare earth metal oxide is formed by a second atomic layer deposition (ALD) process
Implementation Method 2
The amorphous bottom coating provides strong adhesion to the substrate
Implementation Method 3
The top crystalline layer of yttria, with cubic crystal structure and small grain size, exhibits a higher hardness and shows excellent ion bombardment resistance and plasma radical erosion resistance
Data Source
AI summary
A method includes forming a first coating comprising amorphous rare earth metal-containing oxide on a surface of an article using a first atomic layer deposition (ALD) process that includes repeating a process of alumina deposition cycles followed by rare earth metal oxide deposition cycles N1 times. The method also includes forming a second coating comprising crystalline rare earth metal oxide on the first coating using a second ALD process. The method also includes forming a third coating comprising amorphous rare earth metal-containing oxide on the second coating using a third ALD process that includes repeating a process of alumina deposition cycles followed by rare earth metal oxide deposition cycles N2 times. The method also includes forming a fourth coating comprising crystalline rare earth metal oxide on the third coating using a fourth ALD process. In some embodiments, a ratio of N1 to N2 is between about 100 and about 150.