Y2O3 Composite Coating for Plasma Etching Chamber Erosion Resistance
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Solution Overview
Problem
Current protective coatings for IC device plasma etching chambers are prone to failure during high-power etching due to high porosity and mismatch in thermal expansion coefficients between ceramic coatings and metal substrates, leading to reduced mechanical properties and corrosion resistance.
Innovation Solution
A double-layer composite protective coating is prepared using plasma spraying technology to form a metal+Y2O3 transition layer and cold spraying technology to deposit high-purity Y2O3 ceramic coating, ensuring a dense and well-bonded coating with reduced porosity and enhanced bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma spraying technology is used to prepare ceramic coating, then plasma erosion resistance is improved, but porosity increases
Solution Approach 1:
The coating is divided into two distinct layers: a plasma sprayed metal+Y2O3 transition layer and a cold sprayed high-purity Y2O3 top layer. Each layer serves a specific function - the transition layer provides bonding and gradual thermal expansion transition, while the top layer provides dense plasma erosion resistance.
Solution Approach 2:
The invention uses composite materials in two ways: (1) The transition layer is a composite of metal and Y2O3 ceramics sprayed together, and (2) The overall coating structure is a composite of two different ceramic materials (metal+Y2O3 and high-purity Y2O3) deposited by different technologies. This composite approach allows optimization of each layer for its specific function.
2Reliability
If thermal spraying is used to prepare high-purity yttria coating, then plasma erosion resistance is improved, but transverse cracks and non-density occur
Solution Approach 1:
The invention changes the deposition parameters by using cold spraying technology for the top layer instead of thermal spraying. Cold spraying operates at lower temperatures and higher velocities, which prevents the formation of transverse cracks and ensures dense coating without the defects associated with high-temperature thermal spraying.
Solution Approach 2:
The plasma sprayed metal+Y2O3 transition layer acts as an intermediary between the substrate and the cold sprayed high-purity Y2O3 top layer. This intermediate layer provides a gradual transition in thermal expansion coefficients and creates a stable foundation that prevents crack formation in the top layer.
3Manufacturing precision
If cold spraying is used to deposit high-purity Y2O3 coating, then density is improved, but deposition difficulty increases due to particle size constraints
Solution Approach 1:
The coating preparation is segmented into two separate deposition processes, each optimized for its specific layer. The transition layer is deposited first to create a suitable surface, then the top layer is deposited with controlled particle sizes for optimal cold spraying performance. This segmentation simplifies the overall process by breaking down the complex requirements into manageable stages.
4Reliability
If ceramic coating is applied directly on metal substrate, then plasma erosion resistance is improved, but interface bonding strength decreases due to thermal expansion mismatch
Solution Approach 1:
The plasma sprayed metal+Y2O3 transition layer serves as an intermediary between the metal substrate and the high-purity Y2O3 top layer. This intermediate layer has thermal expansion properties that are intermediate between the metal substrate and the ceramic top layer, creating a gradual transition that reduces thermal stress and improves interface bonding strength.
Solution Approach 2:
The transition layer is a composite material combining metal and Y2O3 ceramics, which allows tuning of the thermal expansion coefficient to match both the substrate and the top layer. This composite approach provides both mechanical bonding strength and thermal compatibility at the interface.
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 (metal+Y2O3)/Y2O3 composite coating achieves improved plasma erosion resistance, reduced porosity, and increased interface bonding strength, extending the service life of the plasma etching chamber and enhancing its protective effect.
Implementation Method 1
In plasma spraying process, after being injected into the high-temperature plasma jet, metal or non-metal powders are accelerated and sprayed at high speed onto the surface of the pre-treated workpiece in a molten or semi-melted state under the action of a high-speed jet
Implementation Method 2
The basic principle of cold spraying technology is that the supersonic air flow carries spray powders to hit the surface of the substrate material at a very high speed (usually in a range of 400-1200 m/s), so that strong plastic deformation occurs on the surface of the substrate material and the spray powders are deposited on the surface of the substrate to form a coating
Data Source
AI summary
Through the plasma spraying technology and the cold spraying high-speed deposition technology, an evenly distributed protective coating is formed on the surface of a plasma etching chamber. The protective coating, having a double-layer composite structure, includes a metal+Y2O3 coating as a metal+Y2O3 transition layer deposited by plasma spraying as a lower layer of the double-layer composite structure, and a high-purity Y2O3 ceramic coating coated on the metal+Y2O3 transition layer as an upper layer of the double-layer composite structure, the metal+Y2O3 transition layer is configured to reduce the difference in expansion coefficient between the Y2O3 ceramic coating and the metal substrate, and enhance the bonding force between the Y2O3 ceramic coating and the metal substrate; the high-purity Y2O3 ceramic coating is formed by depositing Y2O3 ceramic powders on the metal+Y2O3 transition layer at high speed through cold spraying high-speed deposition.