Boron Carbide Focus Ring for Uniform Plasma Etching
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Solution Overview
Problem
The non-uniform plasma distribution in plasma etching systems leads to poor quality of microelectronic devices due to the imbalance in plasma treatment, and the focus ring is often etched, requiring frequent chamber openings for replacement, which reduces fabrication yield.
Innovation Solution
A manufacturing method for a ring-shaped element using boron carbide with specific thermal and corrosion-resistant properties, produced through a process involving slurry preparation, granulation, molding, sintering, and shaping, to create a consumable focus ring that minimizes etching and maintains uniform plasma distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high power is applied to maximize plasma distribution, then plasma generation efficiency is improved, but plasma uniformity deteriorates due to standing waves and skin effect
Solution Approach 1:
The focus ring introduces localized structural variation at the electrode edge to modify plasma distribution characteristics. By creating a specific geometric feature (the ring structure) at the edge region, the plasma density is locally adjusted to compensate for the central concentration effect, achieving more uniform overall plasma distribution while maintaining high power operation.
2Stability of the object's composition
If a focus ring is used to correct plasma imbalance, then plasma uniformity is improved, but the focus ring is etched requiring frequent replacement
Solution Approach 1:
The focus ring is constructed from a composite structure comprising a substrate and a coating layer. The coating layer (such as diamond-like carbon or other protective coatings) provides resistance to plasma etching, while the substrate maintains the structural integrity and optical properties. This composite construction allows the focus ring to withstand prolonged plasma exposure without significant erosion.
Solution Approach 2:
The invention modifies the material parameters of the focus ring by selecting materials with specific properties (high melting point, low etch rate, appropriate optical transmission). By changing the material composition and structure parameters, the focus ring achieves both the functional requirement of plasma uniformity correction and the durability requirement of resistance to plasma etching.
3Ease of manufacture
If conventional materials are used for focus ring, then manufacturing simplicity is maintained, but etching resistance is insufficient
Solution Approach 1:
The focus ring employs a composite material structure with a substrate and a protective coating layer. This composite construction provides enhanced etching resistance while maintaining manufacturing feasibility through established coating technologies such as CVD or PVD processes, balancing material performance with manufacturing practicality.
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 ring-shaped element provides stable, uniform plasma etching with reduced etching rate, minimizing chamber openings and improving fabrication yield by maintaining plasma uniformity and reducing defects in semiconductor devices.
Implementation Method 1
boron carbide with specific thermal and corrosion-resistant properties
Implementation Method 2
The non-uniform plasma distribution on the substrate leads to a serious non-uniformity of the plasma treatment... The focus ring arranged at the edge of the substrate prevents or corrects this imbalance
Data Source
AI summary
A manufacturing method of a ring-shaped element for an etcher, comprises a granulation operation comprising i) a slurry manufacturing process of preparing a slurry by mixing a raw material including boron carbide, a sinterability enhancer with a solvent; and ii) a granulation process of drying the slurry to prepare granulated raw material; a molding operation of manufacturing a green body by molding the granulated raw material; a sintering operation of carbonizing and sintering the green body to manufacture a sintered body; a shape operation of shaping the sintered body to a ring-shaped element for an etcher. The sinterability enhancer comprises one selected from the group consisting of carbon, boron oxide and combinations thereof.