About Tungsten Evaporation Sources

In vacuum evaporation, tungsten boats, filaments, and rods are used to hold and heat the material that is to be evaporated. Tungsten is a popular material used for vacuum evaporation because of its high melting point and low vapor pressure. 

It’s also chemically inert, which makes it ideal for use in a variety of applications such as semiconductor and optical coating. In vacuum evaporation, tungsten, boats, filaments and rods are used to hold and heat the material that is to be evaporated. 

Here’s a closer look at each of these components: 

Tungsten Evaporation Boats

Tungsten boats are used to hold the material that is to be evaporated. They are made from high-purity tungsten and available in different variations to accommodate alternative sample sizes and shapes. The most common shapes are rectangular with a recessed dimple in the center. However, many different geometries exist for this evaporation source.

During vacuum evaporation, the tungsten boat is heated using a power source such as a high-current power supply. As the temperature of the tungsten boat increases, the material inside begins to evaporate and deposit on the substrate.

Tungsten boats are ideal for use with high-melting-point materials, such as titanium. They are also commonly used in the semiconductor industry for thin-film deposition.

Tungsten Filaments

Tungsten filaments operate similarly to tungsten boats. However, material (in the form of wire, canes, or clips) is held onto these sources due to how material wets onto the surface area of the filament. This type of source can be versatile and have low operating costs.

• Tungsten filaments can withstand extremely high temperatures without melting, which is essential for high-temperature electronics.
• Filaments can provide focused evaporation while requiring low power to operate.
• Stranded filaments increase surface area, enabling more material to wet onto the source.
• The strength of tungsten filaments ensures a longer operational life compared to other materials, reducing the frequency of replacements.

These filaments are made from high-purity tungsten wire and are available in a variety of diameters and lengths. For varying applications, ranging from optical to semiconductor coatings, this type of source is easily customizable upon request.

Tungsten Rods

Tungsten rod sources are similar to tungsten filaments in that they also operate using the wetting principle. However, this source is more durable than typical tungsten filaments, making it an option for corrosive materials.

The tungsten rod is wrapped with layers of tungsten wire to increase its surface area, and evaporation material is wrapped on top of this tungsten wire. This can also be preloaded with material such as nickel, making it ready-to-use upon receipt — contact R.D. Mathis Company for more details.

R.D. Mathis Company’s Tungsten Boats, Filaments, and Rods

R.D. Mathis Company specializes in creating parts and components from the highest-quality materials, with the largest and most diverse selection of evaporation materials and sources. 

Visit our website to shop for our tungsten boats, filaments, and rod sources.