ALD Protective Coating for Halide Plasma Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for depositing protective coating films on semiconductor chamber components fail to provide conformal coverage, especially on surfaces with high aspect ratios, leading to contamination, corrosion, and erosion due to halogen-containing plasma exposure, as they cannot effectively coat complex features and anodized aluminum surfaces have pores that allow halogen diffusion.
Innovation Solution
The use of atomic layer deposition (ALD) to form a protective coating film comprising a seed layer, a rare-earth containing oxide layer, and a diffusion barrier, with the rare-earth oxide layer being exposed to fluorine-containing plasma to create crystallites of rare-earth fluoride, ensuring complete and uniform coverage on complex surfaces and preventing halogen ion diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional PVD, CVD, sputtering, or spray coating methods are used to deposit protective coating films, then the deposition process can be completed, but conformal coverage on surfaces with high aspect ratios is not achieved
Solution Approach 1:
The patent employs atomic layer deposition (ALD) which fundamentally changes the deposition mechanism from line-of-sight physical vapor deposition to a chemical vapor deposition process with self-limiting surface reactions. This parameter change in deposition methodology enables conformal coating on complex surfaces with high aspect ratios, achieving uniform coverage that conventional methods cannot provide
Solution Approach 2:
The patent replaces mechanical spray coating methods with a chemical deposition process (ALD). Instead of mechanically projecting material onto the surface, the process uses sequential chemical reactions where precursors diffuse into pores and react on surfaces, enabling complete penetration and conformal coating of complex geometries
2Reliability
If anodized aluminum surfaces are used as substrate, then the surface has protective properties, but pores in the anodized layer allow halogen diffusion into chamber components
Solution Approach 1:
The patent acknowledges the porous structure of anodized aluminum surfaces and uses ALD to deposit coating material that penetrates and fills these pores. The self-limiting nature of ALD reactions ensures complete pore penetration and filling, creating a dense, non-porous protective layer that prevents halogen diffusion while maintaining the underlying anodized structure
Solution Approach 2:
The patent creates a composite structure by depositing rare-earth metal-containing oxide layers over the anodized aluminum surface. This composite system combines the corrosion resistance of the anodized layer with the plasma resistance and pore-blocking properties of the ALD-deposited oxide coating, achieving both protection functions simultaneously
3Reliability
If spray coated rare earth metal-containing oxides are used, then protective coating is formed, but pores of 0.01-10 μm remain allowing halogen atom diffusion
Solution Approach 1:
The patent changes the deposition parameters from spray coating (producing micrometer-scale pores) to atomic layer deposition (producing nanometer-scale dense films). The ALD process parameters—sequential precursor exposure, self-limiting reactions, and low deposition rates—create a coating with pore sizes orders of magnitude smaller than the 0.01-10 μm pores in spray coatings, effectively blocking halogen diffusion
Solution Approach 2:
The patent replaces the mechanical spray deposition process with a chemical vapor deposition process. Instead of mechanically projecting molten or suspended oxide particles that form porous structures, the ALD process uses vapor-phase precursors that chemically react on the surface in monolayer increments, creating a dense, pore-free coating structure
4Manufacturing precision
If ALD process is used to deposit protective coating film, then conformal deposition on complex surfaces is achieved, but multiple process steps are required
Solution Approach 1:
The patent segments the protective coating into multiple functional layers deposited by ALD: a seed layer for nucleation, intermediate oxide layers for conformal coverage, and a top rare-earth metal oxide layer for plasma resistance. Each layer performs a specific function, and the segmented structure enables conformal deposition on complex surfaces while managing process complexity through functional decomposition
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 ALD-based method achieves conformal and complete deposition on topologically complex surfaces, significantly reducing contamination and extending the lifespan of chamber components by providing enhanced plasma resistance and mechanical, electrical, and thermal properties.
Implementation Method 1
depositing a seed layer on a surface of an article via an atomic layer deposition (ALD) process, depositing a rare-earth containing oxide layer on the seed layer via an ALD process
Implementation Method 2
exposing the rare-earth containing oxide layer to fluorine-containing plasma
Implementation Method 3
create crystallites of rare-earth fluoride
Implementation Method 4
depositing a diffusion barrier layer prior to depositing the rare-earth containing oxide layer
Data Source
AI summary
A method of forming a protective coating film for halide plasma resistance includes depositing a seed layer on a surface of an article via an atomic layer deposition (ALD) process, depositing a rare-earth containing oxide layer on the seed layer via an ALD process, and exposing the rare-earth containing oxide layer to fluorine-containing plasma.