Why Silicon Carbide Is Replacing Alumina in Semiconductor Etch Rings

Semiconductor equipment manufacturers spend millions of dollars each year to improve plasma etching performance, but a small component can affect chamber uptime, particle size, and wafer yield—that is the etching ring.

High-purity alumina has always been the preferred material for the focusing ring and edge ring in plasma etching equipment. However, with the rapid development of current technology, the performance requirements for chamber components are also gradually increasing. The goal is not only to ensure normal operation within the chamber, but also to maintain maximum dimensional stability, minimize particles, and sustain stable plasma conditions throughout the entire process.

Currently, silicon carbide is gradually replacing alumina as the preferred choice for semiconductor etching rings, for the following reasons.

Premature Wear and Particle Generation

Because the focusing ring is mounted around the wafer to control plasma distribution, it is exposed to conditions such as CF₄, NF₃, SF₆, Cl₂, BCl₃, and radio frequency electromagnetic fields for extended periods during operation. This exposure continuously erodes the surface of the etching ring, leading to changes in uniformity, shortened lifespan, and increased maintenance frequency. In this environment, replacing worn components is not only a matter of material costs, but each maintenance cycle may also lead to equipment downtime and production interruptions.

Material Comparison

In plasma etching applications, the key difference lies not in electrical properties, but in the combined effects of hardness, thermal conductivity, and resistance to surface degradation. These characteristics directly influence the wear rate of components and the amount of contamination that may occur during use.

Four Reasons SiC Has Become a Preferred Etch Ring Material

1.SiC has a much higher hardness than aluminum oxide.

The ultra-high hardness of silicon carbide provides it with superior resistance to surface wear, enabling it to maintain its shape without deformation for a longer period of time.

2.Lower risk of particulate pollution

Silicon carbide can maintain its surface integrity more effectively under harsh processing conditions, and is therefore often used in applications where the primary goal is to reduce particle size.

3.Excellent thermal conductivity

The thermal conductivity of SiC is second only to that of aluminum nitride among these materials and is 3.5 times higher than that of alumina ceramics, enabling it to effectively stabilize component temperatures.

4.Extra long service life

In our actual processing, many customers have reported that replacing alumina with silicon carbide significantly extends the maintenance cycle of parts.

Which Type of Silicon Carbide Is Used in Etch Equipment?

It is important to understand that not all silicon carbide is the same; even alumina has different purity grades.

Reaction-Bonded Silicon Carbide (RB-SiC)

Suitable for large parts, with high mechanical strength

Sintered Silicon Carbide (SSiC)

Higher density, wear resistance and dimensional stability

CVD Silicon Carbide Coatings

High-purity silicon carbide with a dense, non-porous surface

Bulk CVD Silicon Carbide

Highest purity SiC

Selecting the Right Material

There is no universal material for every plasma-facing component.

Alumina remains a practical choice for many insulating and structural applications.

However, for focus rings and edge rings that must simultaneously deliver wear resistance, thermal stability, and long service life, silicon carbide is gradually replacing alumina in the market.

Jundro Ceramics provides custom silicon carbide machining services for semiconductor equipment manufacturers, research institutions, and advanced technology companies worldwide. Whether you require prototype development or high-precision production components, our team can support your project with reliable manufacturing solutions and fast technical assistance.