TaC coated graphite heater

Why choose Semixlab?

Semixlab can provide TaC coated graphite heaters in customized sizes and specifications based on customers' specific equipment models and process requirements. Please contact us for a detailed list of technical parameters, including but not limited to:

- Dimensional tolerances

- Maximum operating temperature

- Physical property data such as thermal conductivity

- Graphite grades and purity

- TaC coating thickness range and uniformity criteria

More importantly, Semixlab's heating elements are made of a high-purity graphite substrate coated with a high-density TaC (Tantalum Carbide) coating, which provides a combination of excellent thermal conductivity and This combines excellent thermal conductivity with high temperature stability. We use graphite materials from the world's top three well-known suppliers, and our long-term stable partners include SGL (Germany), Toyo Tanso (Japan), and Mersen (France), to ensure that our products have excellent quality assurance from the source. At the same time, Semixlab's TaC coating process is at the leading level in the industry, with its denseness, adhesion and corrosion resistance having been verified through many rounds of process validation, and has been widely used in high-end SiC epitaxial equipment, which is highly trusted by customers.

Core Application: Critical Heating Base in SiC Epitaxy Equipment

Semixlab's TaC-coated graphite heaters play a critical role in SiC epitaxy equipment. Its main function is to act as a base for the heating system, carrying and uniformly heating the Wafer Susceptor placed above it.

Structural Levels: In a typical SiC epitaxial chamber, the structure is usually as follows:

1. TaC-coated graphite heater (Semixlab Product): Located on the bottom level, it is the main source of heat.

2. Wafer Susceptor: Placed on top of the heater, the wafer susceptor is also usually made of high purity graphite or other high temperature resistant material and may be coated. Its precision designed grooves are used to hold SiC wafers.

3. SiC Wafers (Wafer): Placed on a carrier disk, they are the substrate for the final growth of the epitaxial layer.

Heating Process and Challenges:

1. High Temperature Requirements: SiC epitaxial growth typically requires extremely high temperatures (typically over 1500∘C or higher) to ensure efficient precursor gas decomposition and the formation of high-quality, single-crystalline SiC layers on the surface of the wafers. Semixlab's heaters are based on a substrate of high-purity, high-thermal-conductivity graphite to ensure that the required high temperatures are reached and sustained in a fast, uniform manner. The Semixlab heater uses high purity graphite with high thermal conductivity as the substrate to ensure that the required high temperature is reached and maintained quickly and uniformly.

2. Uniformity is critical: The temperature uniformity of the heater surface directly affects the temperature distribution of the carrier disk, which in turn determines the consistency of the growth rate, epitaxial layer thickness, and doping concentration at each point on the wafer. Any temperature gradient can lead to increased defects in the epitaxial layer and greater variance in device performance, and Semixlab optimizes the thermal field distribution of the heater to minimize temperature variance through a sophisticated design and manufacturing process.

3. Chemical Stability Challenges: Extremely corrosive gases (e.g., silane, propane, hydrogen, and dopant gases) are passed through the epitaxial process. At high temperatures, these gases are highly aggressive to common graphite, causing premature damage to graphite components and releasing carbon particles that contaminate the reaction chamber and wafers, severely impacting the quality of the epitaxial layer and device yield.

Semixlab TaC Coating Solution and Benefits:

It is in response to these challenges that Semixlab employs advanced Tantalum Carbide (TaC) coating technology. TaC Coating gives graphite heaters superior performance:

1. Reduced Particle Generation and Improved Yield: By effectively preventing the erosion and chalking of the graphite substrate, TaC Coating reduces the source of particulate matter from the process chamber at the source. By effectively preventing the erosion and pulverization of the graphite substrate, the TaC coating reduces the source of particulate matter in the process chamber from the source, which is critical for the production of high-quality SiC epitaxial wafers with a low defect density, and directly contributes to the yield of the final device.

2. Excellent chemical inertness and corrosion resistance: The TaC coating's extremely high chemical stability and low vapor pressure protect the graphite substrate from reacting with process gases at high temperatures and in corrosive atmospheres. This greatly reduces particle contamination due to heater erosion, ensures the purity of the epitaxial growth environment, and improves the quality of the epitaxial layer and device reliability.

3. Process Stability and Repeatability: A stable, long-life heater is the foundation for inter-batch (batch-to-batch) and intra-batch (within-batch) process stability and repeatability, which Semixlab's TaC-coated graphite heaters provide, making your SiC epitaxial process more reliable and controllable.

4. Extended life and reduced operating costs: The denseness and strong adhesion of the TaC coating significantly enhances the durability of the graphite heater, extending its service life under demanding operating conditions. This means less downtime for maintenance and less frequent replacement of spare parts, which effectively reduces the customer's total cost of ownership.

5. Maintaining Excellent Thermal Conductivity: The carefully optimized TaC coating process provides excellent protection while retaining as much as possible of the high purity graphite substrate's excellent thermal conductivity, ensuring that heat is efficiently and uniformly transferred to the wafer carrier tray and wafers above for precise temperature control.