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 device manufacturing, leading to contamination and erosion issues.
Innovation Solution
A thermal spray powder comprising a rare earth element and a first diluent element, such as zinc or silicon, which are present in the form of oxides, is used to form a coating that reduces the size of particles generated during plasma erosion by dispersing weak points in the coating, thereby enhancing plasma erosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal spray coating containing rare earth element is provided on a member exposed to reactive plasma, then the member is protected from plasma erosion, but particles are still generated and deposited on the semiconductor substrate
Solution Approach 1:
The invention changes the chemical composition parameters of the thermal spray coating by introducing diluent elements (such as zinc, silicon, boron, phosphorus, titanium, calcium, strontium, barium, or magnesium) in addition to rare earth elements. This compositional parameter change modifies the coating's erosion characteristics, causing it to generate smaller particles that are more easily removed by plasma and gas flow, thereby reducing deposition on semiconductor substrates while maintaining plasma erosion resistance
Solution Approach 2:
The invention creates a composite thermal spray coating material combining rare earth elements with diluent elements. This composite structure leverages the plasma resistance of rare earth elements while the diluent elements modify the coating's particle generation characteristics. The composite material achieves both protection from plasma erosion and reduced particle deposition on substrates
2Object-generated harmful factors
If the size of particles generated during plasma erosion is reduced, then particles are more easily removed by gas flow and less likely to deposit on the semiconductor substrate, but the coating must be specifically designed to achieve this
Solution Approach 1:
The invention systematically modifies the chemical composition parameters by selecting specific diluent elements from defined groups (first diluent elements: zinc, silicon, boron, phosphorus, titanium, calcium, strontium, barium, magnesium; second diluent elements: aluminum, zirconium, hafnium, niobium, tantalum) and controlling their ratios relative to rare earth elements. This parameter optimization enables the coating to generate smaller particles during plasma erosion without requiring complex multi-layer structures or sophisticated fabrication processes
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 solution effectively reduces the generation of large particles during plasma erosion, improving the plasma erosion resistance of the coating and minimizing contamination on semiconductor substrates, while also reducing the risk associated with the supply of rare earth elements.
Implementation Method 1
a thermal spray coating containing a rare earth element is therefore conventionally provided on a member exposed to reactive plasma during the etching process
Implementation Method 2
microfabrication of a semiconductor substrate, such as a silicon wafer, is performed at times by plasma etching, which is one type of dry etching
Data Source
AI summary
A thermal spray powder of the present invention contains a rare earth element and a diluent element that is not a rare earth element or oxygen, which is at least one element selected, for example, from zinc, silicon, boron, phosphorus, titanium, calcium, strontium, and magnesium. A sintered body of a single oxide of the diluent element has an erosion rate under specific etching conditions that is no less than 5 times the erosion rate of an yttrium oxide sintered body under the same etching conditions.