ALD Plasma-Resistant Coating for High-Aspect-Ratio Chamber Surfaces
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Solution Overview
Problem
Existing methods struggle to deposit coatings uniformly on semiconductor process chamber components with high aspect ratios, leading to poor quality films and potential corrosion or erosion due to high temperatures and plasma exposure.
Innovation Solution
A multi-layer plasma resistant coating is applied using atomic layer deposition (ALD), comprising an amorphous stress relief layer and a rare earth metal-containing oxide layer, which is resistant to cracking and delamination up to 350°C, and is porosity-free, effectively covering features with aspect ratios of 3:1 to 300:1.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coating methods (thermal spray, sputtering, plasma spray) are used, then coating deposition is possible, but uniform coverage on high aspect ratio features (10:1 to 300:1) cannot be achieved
Solution Approach 1:
The coating process is divided into multiple sequential ALD cycles, where each cycle deposits a thin layer uniformly across all surfaces including high aspect ratio features. The segmentation of the deposition process into discrete cycles enables precise control over coating uniformity while accessing difficult-to-reach geometries.
Solution Approach 2:
The patent replaces mechanical coating methods (thermal spray, plasma spray) with a chemical vapor deposition process (ALD). This substitution allows vapor-phase precursors to diffuse into high aspect ratio features and deposit uniformly on all surfaces, overcoming the limitations of particle-based mechanical deposition methods.
2Reliability
If single-layer coatings are used, then deposition process is simple, but resistance to cracking and delamination at high temperatures is insufficient
Solution Approach 1:
The patent employs a composite multi-layer coating structure with alternating layers of different materials (e.g., aluminum oxide, yttrium oxide, erbium oxide). Each layer provides specific functional properties, and the composite structure collectively enhances resistance to thermal stress, cracking, and delamination while maintaining adhesion to the substrate.
Solution Approach 2:
Different layers in the coating structure are designed with specific local properties tailored to their functional requirements. For example, certain layers provide adhesion to the substrate, while others provide thermal barrier properties or plasma resistance. This local optimization of material properties throughout the coating stack enhances overall reliability without excessive complexity.
3Object-affected harmful factors
If coating thickness is increased to improve erosion and corrosion resistance, then protection is enhanced, but stress accumulation leads to cracking and delamination
Solution Approach 1:
The total coating thickness required for erosion and corrosion protection is segmented into multiple thin alternating layers. This segmentation distributes the mechanical stress throughout the coating stack, preventing stress concentration that would lead to cracking and delamination, while maintaining the overall protective function against erosion and corrosion.
Solution Approach 2:
The multi-layer composite coating structure with alternating materials of different mechanical and thermal properties provides both the necessary thickness for protection against erosion and corrosion and the stress management needed to prevent cracking. The composite architecture allows each layer to compensate for the limitations of the others.
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 provides uniform coverage, resistance to corrosion and erosion, and prevents cracking and delamination in extreme environments, enhancing the durability of chamber components.
Implementation Method 1
Each layer of the coating is formed using atomic layer deposition
Implementation Method 2
a first precursor and a second precursor to adsorb onto a surface of the amorphous stress relief layer
Data Source
AI summary
Described herein are articles, systems and methods where a plasma resistant coating is deposited onto a surface of an article using an atomic layer deposition (ALD) process. The plasma resistant coating has a first layer of amorphous Al2O3 on the surface, and a second layer overlaying the first layer, the second layer including a solid solution of Y2O3—ZrO2.