Tag: evaporation materials

Evaporation Pellets for Thin Film Coating

Gold (Au) Evaporation Materials

Evaporation pellets are evaporation materials for vacuum evaporation coating.

Evaporation is a form of physical vapor deposition (PVD) where the evaporation material is heated to a high vapor pressure, often in a molten state. The vapors are then condensed on the substrate to form a thin film.

The most common heating method for vacuum evaporation is the resistance heating method. The advantages of resistance heating method include simple structure, low cost and convenient operation. The disadvantage is that it is not suitable for refractory metals and high temperature resistant dielectric materials. Electron beam heating and laser heating can overcome the shortcomings of resistance heating. Electron beam heating uses a focused electron beam to directly heat the bombarded material, and the kinetic energy of the electron beam becomes thermal energy, causing the material to evaporate. Laser heating uses a high-power laser as a heating source, but due to the high cost of high-power lasers, it can only be used in a few research laboratories. You can refer to Five evaporation sources for heating for detailed information of the heating methods. As for a thin film precious metal coating, the heating is typically accomplished via resistive heating or by E-beam (electron beam).

Evaporation pellets or slugs are manufactured with specific form factors intended to vaporize at known rates. Often during evaporation processes, “spitting” results in liquid droplet material splattering on to the substrate. Engineered pellets are made with specified metal purities and processes intended to minimize incorporated gases and impurities to mitigate “spitting” in process.

Silver (Ag) Evaporation Materials

Optimal evaporative performance for thin film deposition is highly dependent on the use of high purity materials specifically customized for PVD processes. It requires evaporation materials that feature low organic and inorganic impurities, as well as minimal surface contamination. This level of purity results in highly reproducible performance with low spit rates and defects. SAM offers high-quality evaporation materials in precious metals for your PVD coating.

The following chart shows some common thin film deposition of precious metals. SAM can customize any precious metal alloy you need that is not listed.

 Gold Copper Gold Nickel Gold Nickel Indium
Gold Palladium Gold Gold Silicon
Gold Silver Platinum Gold Tin Gold Zinc
Palladium Rhenium Palladium Lithium Palladium Manganese
Palladium Nickel Platinum Palladium Platinum Iridium
Platinum rhodium Silver Gold Silver Titanium

Please visit https://www.sputtertargets.net/evaporation-materials.html for more information.

Manufacturing process of semiconductor wafer

Semiconductor wafers are the basic material for manufacturing chips. The most important raw material for semiconductor integrated circuits is silicon, which is widely found in rocks and gravel in the form of silicate or silicon dioxide in nature. The manufacturing process of semiconductor wafers/silicon wafers can be divided into three basic steps: silicon purification, monocrystalline silicon growth, and wafer formation.

Silicon purification

The sandstone material is placed in a 2000 °C electric arc furnace which has a carbon source. At high temperatures, the silica in the carbon and in the sandstone undergoes a chemical reaction (carbon is combined with oxygen, leaving silicon) to obtain pure silicon having a purity of about 98%, also known as metallurgical grade silicon. Continue reading “Manufacturing process of semiconductor wafer”

Differences between vacuum evaporation and sputter coating

It is well known that vacuum coating has two common methods: vacuum evaporation and sputter coating. However, many people have doubts about the difference between evaporation and sputter coating. Let SAM Sputter Targets answer it for you.

sputter coating3First, let’s take a look at the definition of these two words. The vacuum evaporation is carried out by means of resistance heating, electron beam or laser bombardment in an environment with a vacuum of not less than 10-2 Pa, and the evaporation material is heated to a certain temperature to evaporate or sublimate a large number of molecules or atoms, and then directly deposited on a substrate to form a film. Continue reading “Differences between vacuum evaporation and sputter coating”

What is Extreme High Speed Laser Material Deposition(EHLA)?

The German research institute Fraunhofer Institute for Laser Technology has developed a new metal part coating process called Extreme High Speed Laser Material Deposition (EHLA).

The coating is processed by a laser to form a molten pool with a small amount of powder added. The metal powder is then deposited by laser beam and movement between the components to form a thin, uniform coating. What makes EHLA different from other deposition processes is that the powder melts completely before it is applied to the surface of the part. This process can effectively reduce resource consumption by introducing approximately 90% of the material into the correct area, while other processes can only achieve 50%.

Extreme High Speed Laser Material Deposition

But the most outstanding part of the process is its amazing speed. With the EHLA process, coating processing can be performed at a speed 100 to 250 times higher than conventional laser material deposition speeds. Moreover, it has almost no heat during processing and can be used for heat-sensitive component coating processing. In addition, it is also possible to perform tandem coating processing. In the future, it will be possible for products to be protected from wear and tear during their life cycle.

Researchers say the new process protects metal parts from corrosion and wear without the need to deposit chromium that pollutes the environment. EHLA is environmentally friendly because it does not use chemicals. In addition, the coating adheres to the substrate in a material-locking manner to prevent peeling. And the process is also compatible with other coatings such as iron, nickel and cobalt based alloys. With these advantages, EHLA presents a promising application prospect.

Stanford Advanced Materials (SAM) Corporation is a global supplier of various sputtering targets such as metals, alloys, oxides, ceramic materials. If you are interested, please visit our website https://www.sputtertargets.net/ for more information.

Five evaporation sources for heating

The evaporation source is a heating element used to vaporize  the molding material. The evaporation sources currently used mainly include the following types:

Resistance evaporation heating source

The resistance heating method is simple and easy to operate, and is a common application method: a filament-like or sheet-like high melting point metal (such as Tungsten, Molybdenum, Titanium, etc.) is made into an evaporation source of a suitable shape. It is equipped with an evaporation material to turn on the power supply, and the evaporation material is directly heated and evaporated. The resistance heating method should mainly consider two problems, the melting point and vapor pressure of the evaporation material; the reaction of the evaporation material with the coating material and the wettability caused by the coating material.

Electron beam evaporation source

The evaporation material is placed in a water-cooled copper dry pot and directly heated by an electron beam, which is called electron beam heating. It can vaporize the evaporation material and form a film on the surface of the substrate. It is an important heating method and development direction in the vacuum evaporation coating technology. In the resistance heating method, the coating material and the evaporation material are in direct contact, and the temperature of the evaporation material is higher than that of the coating material, and is easily mixed into the coating material, especially in the semiconductor device coating. Electron beam evaporation can overcome many shortcomings of general resistance heating evaporation, and is particularly suitable for preparing high melting point film materials and high purity film materials.

High frequency induction heating evaporation source

The high-frequency induction heating evaporation source places the graphite or quartz crucible containing the evaporation material in the center of the water-cooled high-frequency spiral coil, so that the evaporation material generates strong eddy current loss and hysteresis loss under the induction of the magnetic field in the high frequency band (to Ferromagnetic), causing the evaporating material to heat up until evaporation. The smaller the volume of the evaporated material is, the higher the frequency of induction is. In the large-scale vacuum aluminum plating equipment on the steel strip, the high-frequency induction heating evaporation process has achieved great success.

Radiant heating evaporation source

For materials with high absorption of infrared radiation, it can be evaporated by radiant heating, and many substances are evaporated by this method. In addition, the reflectivity of the metal for infrared radiation is high, and the absorption rate of quartz for infrared radiation is low, so they are difficult to be evaporated by radiation heating. The main advantage of the radiant heating method is that the evaporation is only heated on the surface, and the adsorbed gas is released on the surface without splashing the material.

Laser beam evaporation source

The evaporation technique using a laser beam evaporation source is an ideal film preparation method because the laser can be installed outside the vacuum chamber. This not only simplifies the space arrangement inside the vacuum chamber and reduces the abandonment of the heating source, but also completely avoids the contamination of the evaporation material by the evaporator, thus it is advantageous for obtaining a high-purity film.

 

Stanford Advanced Materials (SAM) Corporation is a global supplier of various sputtering targets such as metals, alloys, oxides, ceramic materials. If you are interested, please visit our website https://www.sputtertargets.net/ for more information.