How Does a CVD System Work? Chemical Vapour Deposition Explained
A Chemical Vapour Deposition system, commonly known as a CVD system, is used to deposit high purity coatings onto a substrate through controlled chemical reactions inside a heated process chamber.
Thermic Edge designs and manufactures CVD systems and coating equipment for high purity silicon carbide coating applications. These systems support the coating of graphite, porous ceramics and composite components for semiconductor, research and industrial production environments.
The Thermic Edge SiC³ CVD reactor combines a hot wall vertical reactor, controlled gas delivery, induction or resistive heating, component rotation and PLC based process control. These features support repeatable coating thickness, high purity and controlled production across complex components and large batches.
A CVD system brings heating, gas delivery, chamber design and process control together within one coating platform.
The Thermic Edge SiC³ reactor is designed to provide controlled deposition, thermal uniformity, repeatable coating thickness and scalable production.
What Is a CVD System?
A CVD system is a coating machine that provides the controlled heating environment required for chemical vapour deposition. The wider system can also include gas delivery, process control, chamber loading, automation and exhaust management.
Thermic Edge CVD systems are purpose-built to deposit SiC³, the company’s high purity cubic silicon carbide coating. The system can be configured around the coating process, substrate geometry, chamber size and production requirements.
The equipment is designed for applications where coating purity, contamination control, repeatability and throughput are important. This includes semiconductor components, high temperature graphite parts, porous ceramics, composite components and other demanding process hardware.
What Does Chemical Vapour Deposition Mean?
Chemical Vapour Deposition describes the process used by the reactor to deposit a coating through controlled chemical reactions inside a heated chamber.
In the Thermic Edge system, high purity process gases are delivered and mixed before being distributed to the reactor. The heated process environment supports the deposition of cubic silicon carbide onto the loaded components.
The process is managed through controlled gas flow, heating, chamber design, component movement and PLC based automation. Together, these systems support the production of a dense, high purity and conformal SiC³ coating.
The CVD furnace is one part of the complete coating system.
The wider system can also incorporate gas delivery, process control, chamber loading, automation and exhaust management.
How Does a Thermic Edge CVD System Work?
The published features of the Thermic Edge CVD system describe a process built around six main functions:
- Component loading: Graphite, porous ceramic or composite components are loaded into the vertical processing chamber using a motorised chamber lift system.
- Controlled heating: Induction or resistive heating provides the required thermal conditions within the hot wall reactor.
- Gas delivery: High purity process gases are regulated using mass flow controllers and mixed before distribution to the reactor.
- Controlled deposition: LPCVD or atmospheric CVD processing is used to deposit the cubic silicon carbide coating.
- Component rotation: A rotational base helps maximise coating uniformity throughout the loaded components.
- Automated control: A PLC based control system manages the process, with an optional SECS/GEM interface available.
The reactor is available with single or dual process chambers. Chamber size, heating method, gas delivery and process controls can be configured around the coating and production requirements.
| System Function | Thermic Edge Configuration | Published Purpose |
|---|---|---|
| Heating | Induction or resistive heating | Supports the high temperature CVD process. |
| Gas delivery | High purity MFC controlled delivery with Coriolis mixing | Provides precise process gas regulation and mixing. |
| Gas distribution | Multi-zone gas injection | Distributes gases through the processing zone. |
| Component movement | Rotational base | Helps maximise coating uniformity. |
| Loading | Motorised chamber lift | Supports vertical component loading. |
| Automation | PLC control with optional SECS/GEM | Supports automated process control and system integration. |
Hot Wall Vertical CVD Reactor Design
Thermic Edge CVD systems use a hot wall vertical reactor design. The process chamber is manufactured from 316L stainless steel and can be supplied in different sizes.
The available processing zones are:
- Ø300 mm by 450 mm height with induction heating.
- Ø1000 mm by 1500 mm height with resistive heating.
- Ø1500 mm by 2000 mm height with resistive heating.
Single or dual process chamber arrangements can be configured according to production requirements. The system uses a motorised chamber lift for vertical loading and includes a rotational base to maximise coating uniformity.
The modular system footprint is optimised for cleanroom integration and scalability. This allows the CVD platform to support smaller processing zones and larger production-scale coating requirements.
Heating Within a CVD System
Heating is a central part of the chemical vapour deposition process. Thermic Edge CVD systems are available with resistive or induction heating according to the application and the power limitations at the installation site.
The published maximum substrate temperature is up to 1400°C, depending on the process and materials.
Thermic Edge also manufactures specialist CVD heaters for chemical vapour deposition applications. These heaters are designed to provide precise and stable heating within vacuum or controlled atmosphere environments.
Thermic Edge states that temperature stability and heating uniformity are important because fluctuations in temperature can affect film quality. Its CVD heater range is designed around high temperature capability, customisable chamber configurations, vacuum compatibility and rapid thermal response.
Controlled heating supports the chemical reactions required for CVD coating.
Thermic Edge CVD systems use induction or resistive heating, with maximum substrate temperatures up to 1400°C depending on the process and materials.
Controlled Gas Delivery
The Thermic Edge SiC³ system uses SiCl₄, CH₄, H₂ and Ar process gases. These gases are supplied through a high purity delivery system.
Mass flow controllers regulate the gases, while Coriolis mixing takes place before distribution to the reactor. Multi-zone gas injection provides controlled gas delivery through the processing chamber.
The gas delivery arrangement is one of the main features of the system. Thermic Edge identifies controlled gas flow, thermal uniformity and precise process management as important parts of producing consistent, high purity coatings across batches of components.
Thermic Edge process gases:
SiCl₄, CH₄, H₂ and Ar are delivered using high purity MFC controlled equipment, with Coriolis mixing and multi-zone injection.
LPCVD and Atmospheric CVD Processing
Thermic Edge CVD equipment can be configured for low pressure chemical vapour deposition, known as LPCVD, or atmospheric chemical vapour deposition, also known as APCVD.
The deposition process can be customised according to the coating material, chamber size, substrate geometry and production requirements.
This allows the CVD system to be configured around the intended coating process rather than supplied as one fixed standard package.
Thermic Edge can discuss processing zone dimensions, heating method, gas flow control and component loading requirements as part of a CVD system enquiry.
How Does the System Support Coating Uniformity?
The Thermic Edge reactor combines controlled gas flow, thermal uniformity, multi-zone gas injection and a rotational base.
The rotational base is included to maximise the uniformity of deposition. The process gas delivery system uses precision MFC regulation, while the hot wall reactor provides the controlled high temperature processing environment.
Thermic Edge states that its SiC³ coating can achieve thickness uniformity of ±10 µm on a 100 µm layer.
The coating also provides high conformity on complex three dimensional shapes and blind holes, including Ø1 mm by 5 mm geometries.
Coating uniformity is supported through controlled gas delivery, thermal uniformity and component rotation.
The Thermic Edge SiC³ process can achieve ±10 µm thickness uniformity on a 100 µm coating.
Coating Growth Rate and Thickness
The Thermic Edge SiC³ CVD system has a published growth rate of 50 to 60 µm per hour.
A typical SiC³ coating is between 80 and 100 µm thick. Coating thickness can be varied up to 200 µm upon request.
The system has been designed for high volume production environments where throughput, repeatability and contamination control are important.
Single or dual process chamber capability, multiple processing zone sizes and modular construction allow the system to support different production requirements.
| Coating Parameter | Thermic Edge Specification |
|---|---|
| Coating material | Cubic silicon carbide, also known as β-SiC |
| Typical thickness | 80 to 100 µm |
| Maximum thickness | Variable up to 200 µm upon request |
| Growth rate | 50 to 60 µm per hour |
| Thickness uniformity | ±10 µm on a 100 µm layer |
| Process repeatability | Less than 2% variation across a batch under standardised conditions |
| Surface roughness | Adjustable, with Ra tailored to application requirements |
| Coating purity | Below 5 ppm impurities achievable |
What Is SiC³ Coating?
SiC³ is the Thermic Edge trade name for its high purity cubic silicon carbide ceramic coating. It is applied to components using a high temperature, high purity CVD reactor.
The coating is used to protect components from oxidation or reactions with gases at high temperature. Thermic Edge describes SiC³ as an electrical insulator with high hardness and good corrosion and oxidation resistance.
The coating has a 3C cubic beta crystal structure. Its high density helps improve corrosion resistance, wear resistance and component life.
More information about the coating, its properties, materials and applications is available on the Thermic Edge SiC³ silicon carbide coating page.
SiC³ Coating Properties
Thermic Edge publishes the following typical properties for its SiC³ coating:
| Property | Published Value |
|---|---|
| Density | 3200 kg/m³ |
| Crystal structure | 3C cubic β structure |
| Porosity | 0%, helium leak tight |
| Crystal size | 1 to 5 µm |
| Appearance | Grey, satin to dull |
| Thermal expansion from room temperature to 400°C | 4.2 × 10−6 m/K |
| Thermal conductivity at 20°C | 200 W/m·K |
| Elastic modulus | 450 GPa |
| Electrical resistivity at 20°C | 1 MΩ·m |
High Purity CVD Coating
Thermic Edge states that impurity levels below 5 ppm are achievable using high purity gases during the coating process.
The SiC³ coating is also available with low nitrogen absorption, and a nitrogen-free option is available.
Impurity testing was carried out by EAG Laboratories using Glow Discharge Mass Spectrometry. The published impurity measurements were taken 5 µm into the silicon carbide coating.
The Thermic Edge CVD reactor has been developed for applications where coating purity and contamination control are important, including semiconductor and advanced material processing environments.
Surface Roughness and Crystal Size
Thermic Edge can control the crystal size of its SiC³ coating. This allows the coating surface to be produced with different levels of roughness according to the application.
The published typical surface roughness values are:
- Ra = 0.8 µm.
- Rz = 5 µm.
- Rt = 8 µm.
The standard SiC³ coating has a medium surface roughness. Thermic Edge states that larger crystal sizes and rougher coatings have proved suitable for high temperature processes such as silicon carbide epitaxy.
Surface roughness is listed as an adjustable system parameter, with Ra tailored to application requirements.
Coverage of Blind Holes and Complex Components
The Thermic Edge CVD system is designed to provide high conformity across complex three dimensional shapes and blind holes.
Thermic Edge states that its SiC³ coating can provide 30% of the main coating thickness at the bottom of a Ø1 mm by 5 mm deep blind hole.
The coating page also records a test involving a hole approximately 1.2 mm in diameter and 5.5 mm deep. SEM analysis showed that a SiC³ layer remained present at the bottom of the hole.
This coating coverage supports components with internal features where protection of the underlying material is important.
Published geometry capability:
High conformity on complex three dimensional shapes and blind holes, including Ø1 mm by 5 mm geometries.
SiC³ Coating Adhesion
Thermic Edge states that the coating must cover all areas exposed to the process environment, adhere to the component and remain free from cracking after coating.
The SiC³ process is carried out at high temperature using ultrapure gases, including hydrogen. Thermic Edge states that hydrogen cleans the surface by removing oxides and other contaminants that could interfere with adhesion.
During the initial stages of the process, deposition and etching further clean the interface between the base material and the coating.
The porosity of graphite allows the coating process to penetrate the surface. Thermic Edge states that this penetration provides additional support for adhesion.
Coating adherence is tested using fracture surfaces from test plates. Thermic Edge describes this as a destructive test that would reveal poor adhesion through coating flaking.
Graphite Components and CVD Coating
Graphite is used in semiconductor and high temperature applications because of its chemical, mechanical, thermal and electrical characteristics.
Thermic Edge states that graphite can react with surrounding gases when used at high temperature or in plasma environments. Its porosity can also store substances that may interact with the process.
Applying SiC³ seals the graphite porosity and combines the characteristics of graphite with the chemical stability of the silicon carbide coating.
Thermic Edge selects high purity isostatic graphite for demanding semiconductor applications and can manufacture the base component before applying the coating.
Customers can explore Thermic Edge graphite components and machining capabilities or provide suitable parts for coating.
Ceramic and Composite Components
The Thermic Edge CVD system lists porous ceramics and composite materials among its supported substrate types.
The SiC³ coating page identifies silicon-based ceramics such as silicon carbide, silicon-infiltrated silicon carbide and silicon nitride as suitable coating materials.
For these ceramic components, the coating can improve corrosion resistance and block the diffusion of impurities from the base material.
Thermic Edge has also developed experience coating carbon composite components intended for high temperature applications. The properties and thermal expansion of the composite material must be considered as part of the coating process.
Semiconductor Applications
The Thermic Edge SiC³ CVD reactor is designed for high volume production environments, including semiconductor applications where throughput, repeatability and contamination control are critical.
Typical semiconductor and electronics applications include:
- Wafer carriers.
- Susceptors.
- Heating elements.
- Graphite process components.
- Components used in MOCVD processing.
- Components used in epitaxial processing.
- Process hardware requiring high purity silicon carbide coatings.
The coating is intended to protect these components from corrosive and reactive processing environments.
Other SiC³ Coating Environments
Thermic Edge lists the following high temperature environments and processes for its SiC³ coating:
- Oxygen.
- Hydrogen.
- Nitrogen.
- Sulphur.
- Ammonia.
- Hydrogen chloride.
- Methane and other hydrocarbons.
- Carbon monoxide and carbon dioxide.
- MOCVD processing.
- Epitaxial processing.
- Rapid thermal processing.
- CVD, PECVD and PVD thin film deposition.
- High vacuum, with a reduced maximum operating temperature.
- Inert atmospheres.
- RF and DC plasma processes.
The coating is also suitable for vacuum furnace components and sample heating equipment used in vacuum, reactive and oxygen environments.
PLC Control and Process Repeatability
The Thermic Edge CVD system uses PLC based control. An optional SECS/GEM interface is available for integration with wider manufacturing systems.
The published process repeatability is less than 2% variation across a batch under standardised conditions.
Controlled gas delivery, heating, component rotation and automated process management support repeatable coating production across large component batches.
The modular system design is optimised for cleanroom integration and scalable deployment.
Production Capacity and Scalability
Thermic Edge CVD systems are available with processing zones ranging from Ø300 mm by 450 mm height to Ø1500 mm by 2000 mm.
Production-related features include:
- Single or dual process chambers.
- Induction or resistive heating.
- A growth rate of 50 to 60 µm per hour.
- Motorised vertical loading.
- Component rotation.
- Multi-zone gas injection.
- PLC based automation.
- Optional SECS/GEM integration.
- Modular construction.
- Cleanroom integration.
The SiC³ reactor has been engineered to support high volume production while maintaining repeatability, coating purity and controlled thickness.
The Thermic Edge CVD platform is designed for scalable coating production.
Multiple chamber sizes, dual chamber capability, controlled gas delivery and automated process management support demanding industrial environments.
Thermic Edge CVD System Specifications
| System Parameter | Specification |
|---|---|
| Reactor type | Hot wall vertical CVD reactor |
| Process chambers | Single or dual chambers |
| Heating method | Resistive or induction heating |
| Chamber material | 316L stainless steel |
| Coating material | Cubic silicon carbide, β-SiC |
| Deposition process | LPCVD or atmospheric CVD |
| Processing zones | Ø300 mm × 450 mm, Ø1000 mm × 1500 mm or Ø1500 mm × 2000 mm |
| Maximum substrate temperature | Up to 1400°C depending on process and materials |
| Process gases | SiCl₄, CH₄, H₂ and Ar |
| Gas control | MFC controlled delivery, Coriolis mixing and multi-zone injection |
| Loading | Motorised chamber lift |
| Component movement | Rotational base |
| Automation | PLC control with optional SECS/GEM |
| System footprint | Modular and optimised for cleanroom integration |
Frequently Asked Questions About CVD Systems
What is a CVD system used for?
A CVD system is used to deposit high purity coatings onto a substrate through controlled chemical reactions inside a heated process chamber. Thermic Edge systems are designed for silicon carbide coating applications involving graphite, porous ceramics and composite components.
What coating does the Thermic Edge CVD system produce?
The system is designed to produce SiC³, Thermic Edge’s high purity cubic silicon carbide coating. It has a 3C cubic beta crystal structure.
Which CVD processes are available?
Thermic Edge CVD equipment can be configured for LPCVD or atmospheric CVD processing according to the coating process, substrate geometry, chamber size and production requirements.
What is the typical SiC³ coating thickness?
A typical coating is 80 to 100 µm thick. Thickness can be varied up to 200 µm upon request.
What is the coating growth rate?
The Thermic Edge SiC³ process has a published growth rate of 50 to 60 µm per hour.
How pure is the coating?
Impurity levels below 5 ppm are achievable using high purity gases. Low nitrogen absorption and a nitrogen-free option are also available.
Can the system coat complex components?
Yes. The system is designed for high conformity on complex three dimensional shapes and blind holes, including Ø1 mm by 5 mm geometries.
How uniform is the coating?
Thermic Edge states that SiC³ can achieve thickness uniformity of ±10 µm on a 100 µm coating.
Which materials can be coated?
The CVD systems page lists graphite, porous ceramics and composites as substrate types. The wider SiC³ coating service also supports selected silicon-based ceramics, carbon composites and refractory metals.
What automation is available?
The system uses PLC based control, with an optional SECS/GEM interface available for integration with wider manufacturing systems.
Thermic Edge CVD Experience
Thermic Edge has more than a decade of continuous experience operating its own SiC³ CVD reactor.
This practical experience informs the design, optimisation and maintenance of its CVD systems. Thermic Edge also supports component preparation, coating requirements and post-process considerations.
The company can manufacture the base graphite, ceramic or refractory metal component before applying the SiC³ coating. A coating-only service is also available for suitable customer-supplied components.
Conclusion
A Thermic Edge CVD system deposits high purity cubic silicon carbide coatings through controlled chemical reactions within a heated process chamber.
The system combines a hot wall vertical reactor, induction or resistive heating, high purity gas delivery, MFC regulation, Coriolis mixing, multi-zone injection, component rotation and PLC based control.
These features support coating growth rates of 50 to 60 µm per hour, typical thicknesses of 80 to 100 µm, uniformity of ±10 µm on a 100 µm layer and impurity levels below 5 ppm.
With multiple chamber sizes, single or dual chamber configurations and modular construction, the SiC³ reactor supports semiconductor, research and industrial production applications involving graphite, porous ceramics and composite components.
Need to discuss a CVD system or SiC³ coating requirement?
Speak to the Thermic Edge team about substrate material, chamber size, coating thickness, gas delivery and production requirements here:
https://thermic-edge.com/contact/
Or email: sales@thermic-edge.com
