Plasma-Resistant Edge Ring Coating for Dry Etching Reliability
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Solution Overview
Problem
The upper portion of the edge ring in dry etching apparatuses is often damaged by plasma during the semiconductor manufacturing process, particularly in low-temperature environments where polymer protective layers may not form sufficiently to prevent damage.
Innovation Solution
A dry etching apparatus with an edge ring featuring a coating layer on its exposed surface, made of materials like fluorocarbon-based polymers or ceramics, which provides etching resistance to hydrogen and fluorocarbon gases, and an adhesive gel pad between the electrostatic chuck and the edge ring to prevent direct plasma exposure to the lower ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the edge ring is exposed to plasma during dry etching, then the etching process can be performed, but the upper portion of the edge ring is damaged by plasma
Solution Approach 1:
The patent introduces a coating layer as an intermediary substance between the plasma and the edge ring. This coating layer, made of materials such as silicon oxide, silicon nitride, or diamond-like carbon, acts as a protective barrier that allows the plasma to perform etching on the substrate while preventing direct contact and damage to the edge ring structure
Solution Approach 2:
The patent employs composite material structure by combining the edge ring (typically metal or metal alloy) with a coating layer of ceramic or polymer materials. This composite structure provides both the structural integrity of the edge ring and the plasma resistance of the coating material, resolving the contradiction between enabling plasma exposure and preventing damage
2Device complexity
If no coating layer is applied on the edge ring, then the device complexity is reduced, but the edge ring cannot resist plasma damage
Solution Approach 1:
The coating layer is applied in advance to the edge ring surface before the edge ring is installed in the chamber. This preliminary protective action ensures that when the edge ring is subsequently exposed to plasma during etching operations, the damage-resistant coating is already in place, preventing plasma damage without requiring complex real-time protection mechanisms
3Reliability
If the entire edge ring is made of plasma-resistant material, then plasma damage is prevented, but the thermal management capability is reduced
Solution Approach 1:
The patent applies different materials to different parts of the edge ring structure. The upper surface that contacts plasma is coated with plasma-resistant materials (silicon oxide, silicon nitride, or diamond-like carbon), while the bulk structure and lower portions maintain the original metal or metal alloy composition for optimal thermal conduction. This localized differentiation allows simultaneous achievement of plasma resistance and thermal management
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 protects the edge ring from plasma damage, extending its lifespan and increasing the maintenance interval of the etching apparatus, thereby enhancing the reliability and productivity of the dry etching process.
Implementation Method 1
a thermally conductive adhesive gel pad adhered to the lower surface of the annular body
Implementation Method 2
a plasma source configured to generate plasma using the process gas in the process chamber
Data Source
AI summary
A dry etching apparatus includes a process chamber; a support provided in the process chamber and configured to support a substrate; a gas supply configured to supply a process gas including a hydrogen gas (H2) and a fluorocarbon gas (CxFy) into the process chamber; a plasma source configured to generate plasma using the process gas in the process chamber, wherein the support includes: an electrostatic chuck on which the substrate is disposed; an edge ring provided along a circumference of the electrostatic chuck and supporting an edge region of the substrate; an adhesive gel pad provided between the electrostatic chuck and the edge ring; and a coating layer formed only on a surface of the edge ring, which is exposed to the plasma.