Rare Earth Thermal Spray Coating for Plasma Erosion Resistance
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Solution Overview
Problem
Conventional thermal spray coatings containing rare earth elements fail to completely suppress the generation of large particles during plasma etching in semiconductor manufacturing, leading to contamination of semiconductor substrates and erosion of apparatus components.
Innovation Solution
A thermal spray powder comprising a rare earth element and a group 2 element, along with a diluent element, is used to form a coating that reduces the size of particles generated during plasma erosion, thereby minimizing contamination and improving plasma erosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal spray coating containing a rare earth element is used to protect members from plasma erosion, then plasma erosion resistance is improved, but large particles are generated and deposit on semiconductor substrates causing contamination
Solution Approach 1:
The patent applies composite materials by combining rare earth element oxide (providing plasma erosion resistance) with group 2 element oxide (reducing particle generation) and diluent element oxide (controlling coating structure and particle size). This composite coating formulation resolves the contradiction by integrating multiple materials with complementary functions to simultaneously achieve erosion resistance and minimize harmful particle generation.
Solution Approach 2:
The patent applies parameter changes by optimizing the compositional ratios of rare earth element oxide (1-50 mol%), group 2 element oxide (1-50 mol%), and diluent element oxide (10-80 mol%). By adjusting these compositional parameters, the coating achieves optimal balance between plasma erosion resistance and particle generation suppression, transforming the material properties to resolve the technical contradiction.
2Reliability
If the rare earth element content in the thermal spray coating is increased to improve plasma erosion resistance, then erosion resistance is improved, but the rare earth element content in deposited particles exceeds allowable levels
Solution Approach 1:
The patent applies parameter changes by precisely controlling the rare earth element oxide content within 1-50 mol% of the total coating composition. This parameter optimization ensures sufficient plasma erosion resistance while limiting the absolute amount of rare earth elements available to form deposited particles, thereby maintaining contamination levels within allowable specifications.
Solution Approach 2:
The patent applies composite materials by formulating a multi-component system where rare earth element oxide is combined with group 2 element oxide and diluent element oxide. This composite approach distributes the functional requirements across multiple materials, allowing the rare earth content to be kept at optimal levels for erosion resistance without excessive particle contamination.
3Object-generated harmful factors
If the particle size generated from thermal spray coating erosion is reduced, then particle contamination is minimized, but the coating structure must be optimized which increases manufacturing complexity
Solution Approach 1:
The patent applies composite materials by incorporating diluent element oxide (10-80 mol%) specifically to control coating structure and particle size. The diluent element acts as a structural modifier that facilitates the formation of fine particles during plasma erosion while maintaining coating integrity, achieving particle size reduction through material composition rather than complex manufacturing processes.
Solution Approach 2:
The patent applies parameter changes by optimizing the compositional ratios of all three components (rare earth element oxide, group 2 element oxide, and diluent element oxide) to control particle size. By adjusting these compositional parameters, the coating naturally generates smaller particles during erosion without requiring complex manufacturing or post-processing steps.
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 effectively reduces the generation of large particles and contamination on semiconductor substrates, while also optimizing the use of rare earth elements to minimize supply risks and costs.
Implementation Method 1
a member inside a semiconductor device manufacturing apparatus that is exposed to reactive plasma may be subject to erosion (damage) and generate particles
Implementation Method 2
A thermal spray coating containing a rare earth element is therefore conventionally provided on a member exposed to reactive plasma during the etching process
Data Source
AI summary
A thermal spray powder of the present invention contains a rare earth element and a group 2 element, which belongs to group 2 of the periodic table. The thermal spray powder, which contains a rare earth element and a group 2 element, is formed, for example, from a mixture of a rare earth element compound and a group 2 element compound or from a compound or solid solution containing a rare earth element and a group 2 element. The thermal spray powder may further contain a diluent element that is not a rare earth element or a group 2 element and is not oxygen, which is at least one element selected, for example, from titanium, zirconium, hafnium, vanadium, niobium, tantalum, zinc, boron, aluminum, gallium, silicon, molybdenum, tungsten, manganese, germanium, and phosphorus.