What is a SiC Coated ICP Etching Susceptor？

1. The Evolution of Semiconductor Etching Technology

Over the past four decades, semiconductor etching technology has gradually transitioned from isotropic wet chemical etching to highly controllable plasma-based dry etching systems. Among these, Inductively Coupled Plasma (ICP) etching technology has become the cornerstone of advanced process node manufacturing due to its unique ability to independently control plasma density and ion energy.

Modern ICP systems typically operate under extremely harsh conditions, including high-density plasma environments, extremely high operating temperatures, and exposure to highly reactive halogen chemicals such as fluorine gas (F₂), chlorine gas (Cl₂), and sulfur hexafluoride (SF₆). While these conditions are essential for achieving high anisotropic etching performance and precise critical dimension (CD) control, they also pose extremely severe challenges to the materials inside the etch chamber.

With the continuous miniaturization of device geometries and increasingly stringent yield requirements, the performance of internal etch chamber components—particularly wafer support structures—has become a key factor in determining process stability, contamination control levels, and equipment uptime. It is against this backdrop that the importance of SiC-coated functional components has become increasingly prominent.

2. Definition of SiC Coated ICP Etching Susceptor

A SiC Coated ICP Etching Susceptor is a wafer support component precision-engineered specifically for plasma etching environments. Structurally, it primarily consists of the following two parts:

A high-purity, isotropic graphite substrate;

A dense, chemically inert silicon carbide (SiC) coating, typically deposited using a chemical vapor deposition (CVD) process.

The SiC coating formed via the CVD process creates a pore-free, high-purity protective layer with extremely high mechanical strength on the component’s surface, ensuring reliable and stable operation in ultra-clean semiconductor manufacturing environments.

Inside the ICP etching chamber, this tray is typically positioned at or near the interface of the electrode platen; in this location, it can directly support the wafer and also serve as a critical structural support and heat transfer medium connecting the plasma environment to the wafer. Its functional role is akin to a “process interface layer,” acting as a bridge between the physical effects of the plasma and the integrity of the substrate material.

 Liufang semiconductor , a leading Chinese semiconductor coating company, reports that these SiC-coated trays have been widely adopted in ICP etching, MOCVD (metal-organic chemical vapor deposition), and various high-temperature semiconductor processing systems, fully demonstrating their exceptional cross-process compatibility and strategic importance in semiconductor manufacturing workflows.

3. Material Advantages of SiC Coatings in Plasma Etching Environments

The use of SiC coatings in semiconductor etching equipment is by no means coincidental; it represents a material engineering optimization driven by extreme process conditions.

First, silicon carbide (SiC) possesses exceptional chemical inertness. In fluorine- and chlorine-based plasma environments, SiC forms a stable barrier against chemical erosion, thereby significantly reducing particle generation and the risk of contamination.

Second, SiC exhibits exceptional thermal stability, maintaining its structural integrity even at temperatures exceeding 1200°C (and in some cases, even exceeding 2000°C). This property is critical for maintaining dimensional stability and preventing deformation under cyclic thermal loads.

Third, the combination of a graphite substrate with a SiC coating optimizes thermal conductivity and ensures uniform heat distribution; this directly influences wafer temperature uniformity—a key variable for ensuring consistent etch rates and critical dimension (CD) control.

Furthermore, the chemical vapor deposition (CVD) process ensures that the material density is close to the theoretical value and that purity is extremely high, thereby eliminating micro-pores and minimizing impurity diffusion. This is critical for advanced process nodes, where even trace amounts of contamination can lead to yield loss.

Finally, the inherent high hardness and wear resistance of SiC help extend the service life of components, thereby reducing maintenance frequency and total cost of ownership (CoO) for manufacturing facilities.

4. The Functional Role of SiC Coated ICP Etching Susceptor in the Etching Process

From the perspective of process integration, SiC-coated ICP trays play multiple critical roles, serving as both a mechanical interface and a physicochemical interface.

First and foremost, they act as a support platform for the wafer, ensuring precise positioning and surface flatness. Any deviation at this level can propagate downward, potentially leading to lithographic alignment errors or etching non-uniformity.

Equally important is its role in thermal management. During ICP (Inductively Coupled Plasma) operation, ion bombardment and exothermic surface reactions generate localized heat. The tray facilitates controlled heat transfer, thereby stabilizing the wafer’s temperature distribution and ensuring process window repeatability.

In addition to its mechanical and thermal management functions, the tray influences the interaction between the plasma and the surface. As a boundary surface within the plasma sheath region, its material properties affect the local electric field distribution, ion energy transfer, and ultimately the etch profile characteristics (such as sidewall angles and micro-load effects).

Perhaps most critically, the SiC coating acts as a contamination barrier, isolating the underlying graphite substrate from direct exposure to the plasma environment. Without this barrier, graphite oxidation and particle shedding would introduce unacceptable defect densities into advanced semiconductor processes.

In actual fab operations, it is widely recognized in the industry that etch stability, particle control performance, and chamber process repeatability are all highly sensitive to the condition and quality of the tray assembly.

5. China’s Leading Manufacturer of SiC-Coated ICP Trays

Historically, the market for SiC-coated graphite components has long been dominated by suppliers from Japan, Europe, and the United States. However, over the past decade, Chinese manufacturers have made significant strides in both coating technology and large-scale mass production capabilities.

These include Zhejiang Liufang Semiconductor Technology Co., Ltd. , Semixlab Technology , Vetek Semiconductor , and others. Among them, Zhejiang Liufang Semiconductor Technology Co., Ltd. has emerged as a prominent player in the domestic market. The company specializes in the following areas:

● R&D of CVD SiC coating technology

● Manufacturing of graphite-based semiconductor components

● Supply of consumables for ICP etching and epitaxial processes

According to information published on its official platform, the company’s product portfolio includes SiC-coated trays, substrate holders (susceptors), and precision graphite components; these products are widely used in the manufacturing processes of LEDs, SiC power devices, and compound semiconductors.

Looking at the overall development trends of China’s semiconductor industry, three key directions are emerging:

✔ Rapid domestic substitution of critical semiconductor consumables

✔ Expansion of application areas from epitaxial processes to etching and thin-film deposition processes

✔ Continuous improvement in coating uniformity, purity, and defect control

These trends indicate that SiC-coated ICP trays are undergoing a transformation from a niche consumable to a strategically significant, domestically produced core component within China’s semiconductor supply chain.