Multilayer ALD Coating for Process Chamber Components
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Solution Overview
Problem
Current coatings for semiconductor process chamber components are prone to degradation and particle contamination due to their material limitations, leading to short lifetimes and compromised plasma etching and cleaning performance, with existing techniques failing to provide durable, conformal, and ion-resistant coatings for complex surfaces.
Innovation Solution
A rare earth metal-containing oxide coating structure formed by atomic layer deposition (ALD), comprising a single amorphous layer with alternating crystalline layers, providing strong adhesion, ion bombardment resistance, and conformal coverage for complex shapes, using yttrium aluminate and yttria layers to enhance durability and plasma resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional coatings are applied to process chamber components, then initial plasma etching and cleaning performance is maintained, but coating lifetime is short due to degradation and particle contamination
Solution Approach 1:
The patent applies a composite coating structure consisting of multiple layers with different materials and properties. The coating includes a first layer of aluminum oxide or aluminum hydroxide providing adhesion and a second layer of yttrium oxide providing plasma resistance and durability. This composite structure resolves the contradiction by combining materials that individually address different requirements (adhesion vs. plasma resistance), achieving both long lifetime and maintained performance.
Solution Approach 2:
The patent changes the chemical composition and structural parameters of the coating by using specific rare earth metal oxides (yttrium oxide, lanthanum oxide, cerium oxide) with controlled thickness ratios. The second layer thickness is maintained at 5-50 nm to optimize plasma resistance while the first layer provides adhesion. This parameter optimization enables the coating to withstand plasma bombardment for extended periods without degradation.
2Ease of manufacture
If existing coating techniques are used, then coating application is relatively simple, but conformal coverage on complex surfaces is poor
Solution Approach 1:
The patent replaces conventional mechanical coating methods (such as spray coating or dip coating) with atomic layer deposition (ALD). ALD is a chemical vapor deposition technique that deposits materials atom-by-atom in self-limiting reactions, enabling uniform conformal coverage on complex three-dimensional surfaces. This substitution maintains ease of manufacture through automated process control while dramatically improving manufacturing precision in terms of coating uniformity and conformality.
3Strength
If conventional coatings are applied, then initial adhesion is adequate, but resistance to ion bombardment and plasma degradation is insufficient
Solution Approach 1:
The patent uses a composite coating where the first layer (aluminum oxide or aluminum hydroxide) provides strong adhesion to the substrate, while the second layer (yttrium oxide or other rare earth metal oxides) provides resistance to ion bombardment and plasma degradation. The layered composite structure allows each material to perform its specialized function, resolving the contradiction between adhesion strength and plasma resistance.
Solution Approach 2:
The patent applies different materials with different properties to different locations within the coating structure. The first layer near the substrate is optimized for adhesion, while the second layer exposed to plasma is optimized for plasma resistance. This local optimization of material properties at different positions within the coating resolves the contradiction between adhesion and ion bombardment resistance.
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 coating significantly prolongs the lifetime of process chamber components, reduces particle defects, maintains uniform plasma impedance, and prevents cracking, peeling, and delamination, ensuring consistent and repeatable plasma etching and cleaning performance.
Implementation Method 1
a first coating comprising amorphous rare earth metal-containing oxide formed by a first atomic layer deposition (ALD) process
Implementation Method 2
providing strong adhesion, ion bombardment resistance, and conformal coverage for complex shapes
Data Source
AI summary
A method includes: forming a first coating comprising amorphous rare earth metal-containing oxide directly 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 first coating characterized by a first thickness; forming a second coating comprising crystalline rare earth metal oxide on the first coating using a second ALD process, the second coating characterized by a second thickness; 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 third coating characterized by a third thickness; and forming a fourth coating comprising crystalline rare earth metal oxide on the third coating using a fourth ALD process.