Tantalum capillary tubes: An outstanding choice for high-performance components inside CVD reaction chambers
In the design and manufacture of chemical vapor deposition (CVD) equipment, the material selection for the interior of the reaction chamber is the core factor determining the success or failure of the process. These components are directly exposed to high temperatures, highly reactive and strongly corrosive reaction atmospheres, facing severe challenges. Among numerous materials, Tantalum Capillary Tube, with its unique comprehensive performance, is becoming the ideal material for manufacturing key components such as sample holders, gas distributors, and small heating elements inside CVD reactors.
Why choose tantalum capillary tubes as internal components of the CVD reactor?
Tantalum is a refractory metal, and its properties are perfectly matched with the extreme environment requirements of the CVD reaction chamber:
Tantalum has an extremely high melting point of 3017°C, far exceeding the reaction temperatures of most CVD processes (typically 800°C - 1200°C, and up to 2000°C in some applications). Supports or components made from tantalum capillaries can maintain extremely high mechanical strength and shape stability during the process, avoiding process failure or contamination caused by softening, deformation or melting.
Unparalleled corrosion resistance and carburization resistance
CVD processes often employ halides (such as WF6, TiCl4 hydrides (SiH4, NH3), and highly reducing hydrogen (H2) atmospheres. A dense and inert tantalum oxide (Ta2O5) passivation layer forms on the surface of tantalum, effectively resisting the erosion of these highly reactive CVD reaction gases. More importantly, unlike metals such as nickel and iron, tantalum has an extremely low carbon solubility and strong carburization resistance. It is less likely to form brittle carbides in carbon-containing atmospheres (such as CH4), thereby significantly extending the lifespan of components.
Tantalum has excellent thermal conductivity and a certain resistivity, making it an outstanding material for manufacturing small, customized heating elements. By precisely controlling the current, highly localized heat sources can be directly provided by tantalum capillaries.
High purity and low contamination
The CVD process used for semiconductor and optical coating applications has zero tolerance for contamination. High-purity tantalum capillary tubes (with purity up to 99.95% - 99.995%) do not volatilize or form by-products with reactive gases at high temperatures, ensuring the extremely high purity of the deposited films and the performance of the final products.
The specific application scenarios of tantalum capillary tubes inside the CVD reactor. Sample Holders & Susceptors
The support, made by weaving or welding tantalum capillary tubes, is used to fix and carry substrates (such as silicon wafers, sapphire substrates). Its excellent high-temperature strength ensures that the substrate remains flat and stable during the long-term deposition process, and its chemical inertness avoids unnecessary reactions with the substrate backside or reaction gases, eliminating backside contamination.
Gas Distribution Manifolds
By precisely machining a series of micro-holes on tantalum capillaries, an efficient gas distributor can be designed. The corrosion resistance of tantalum ensures that the holes of the distributor will not be blocked or corroded and deformed by reaction by-products during long-term use, thus always providing a stable and uniform gas flow, which is the key to obtaining high-quality and uniform films.
Miniature Heating Elements
When tantalum capillary tubes are bent into specific shapes (such as coils or straight wires) and electrified, they can serve as highly efficient embedded heaters. They are commonly used in:
Local substrate preheating: Provide precise temperature control in specific areas of the substrate.
In-situ preheating and pyrolysis of precursor gas: Activating the gas before it reaches the substrate surface to alter the reaction path.
Scientific-grade CVD reactor: Provides highly flexible and customizable thermal field solutions for special process requirements.
Liners & Shields
The inner lining made of tantalum tubes or plates can protect the water-cooled wall of the reactor body from the influence of deposit films and corrosive gases, simplify maintenance and extend the service life of the main reaction chamber. As replaceable consumables for CVD reactors, they reduce the long-term maintenance costs of the equipment.
How to choose the right tantalum capillary assembly for your CVD equipment?
When selecting tantalum capillaries as internal components, more stringent parameters need to be considered:
Material Purity: High-purity oxygen-free tantalum material must be selected to prevent impurities from volatilizing at high temperatures.
High-temperature recrystallization behavior: It is necessary to understand the grain growth of tantalum tubes at the expected operating temperature, as this will affect their long-term mechanical properties.
Accurate dimensions and forming capabilities: The dimensional tolerances and shape complexity of components are directly related to their functionality and installation accuracy.
Welding and processing performance: Ensure that the supplier has the capability to precisely weld and form tantalum capillaries to meet customized design requirements.
Fortu Tech can produce and process Tantalum Capillary Tube, Tantalum billet, Tantalum sheet&plate, Tantalum foil, Tantalum rod, Tantalum wire, Tantalum tubes, Tantalum target.