Physical Vapor Deposition: Sputter Coating & Evaporation

Physical vapor deposition processes use vacuum technology to create a sub-atmospheric pressure environment and an atomic or molecular condensable vapor source (from a solid or liquid surface) to deposit thin films and coatings. Sputtering deposition and vacuum evaporation are among the more well known.

physical vapor deposition sputtering evaporation

Sputtering deposition

The sputtering deposition is an etching process that alters the physical properties of a surface. In this process, a gas plasma discharge is set up between two electrodes: a cathode plating material (the sputter coater targets) and an anode material (the substrate). The film made by sputter coating are thin, ranging from 0.00005 – 0.01 mm. Chromium, titanium, aluminum, copper, molybdenum, tungsten, gold, and silver are typical sputter coating targets.

Sputter coated films are used routinely in decorative applications such as watchbands, eyeglasses, and jewelry. Also, the electronics industry relies on heavily sputtered coatings and films, such as thin film wiring on chips and recording heads as well as magnetic and magneto-optic recording media. Companies also use sputter deposition to produce reflective films for large pieces of architectural glass used in the automotive industry. Compared to other deposition processes, sputter deposition is relatively inexpensive.

vacuum coating

Vacuum Evaporation

The vacuum evaporation is a process of reducing the wastewater volume through a method that consists of concentrating a solution by eliminating the solvent by boiling. In this case, it is performed at a pressure lower than atmospheric pressure. Thus, the boiling temperature is much lower than that at atmospheric pressure, thereby resulting in notable energy savings. The basic components of this process consist of: evaporation pellets,  heat-exchanger, vacuum, vapor separator, and condenser.

Vacuum evaporation is used in the semiconductor, microelectronics, and optical industries and in this context is a process of depositing thin films of material onto surfaces. High-purity films can be obtained from a source evaporation material with high purity. The source of the material that is going to be vaporized onto the substrate can be a solid in any shape or form (usually pellets). The versatility of this method trumps other deposition processes. Also, when the deposition is not desired, masks are utilized to define the areas on the substrate for control purposes.

Information from Stanford Advanced Materials. Please visit https://www.sputtertargets.net/ for more information.

Smelting Technology of Metal Titanium and Titanium Alloy

In the industrial production of titainum and titanium alloys, the most commonly used techniques are vacuum arc remelting (VAR) and cold hearth melting.

Vacuum Arc Remelting

VAR technology can refine the ingot structure in titanium alloy smelting and improve the purity of the product. The main developments of this technology in recent years are as follows:

  • Fully-automatic VAR re-dissolution process

Advanced computer technologies are applied to VAR processes. For example, automated electronic control box data collection systems can establish excellent smelting modes for specific ingots and alloys. In addition, it can analyze the problems in the smelting process and improve the metal yield.

  • Ingot size enlargement

Large VAR furnaces can smelt titanium ingots with a mass of 30t. At present, the tonnage of vacuum self-consumption arc furnaces for molten titanium is mostly 8-15t.

  • Different power supply methods

The power supply mode adopts a coaxial power supply mode, which can cancel the magnetic field and prevent segregation.

  • Development of numerical simulation technology

Domestic and foreign scholars have made some progress in using the numerical simulation method to study the VAR process. The distribution law of the ingot temperature field has been successfully explored and a model for predicting the solidification microstructure, ingot composition and defect distribution has been established.

Cold hearth Melting

Cold hearth melting uses a plasma (Plasma Arc) or an electron beam (Electron Beam) as a heat source, and can be divided into two processes of plasma cold bed furnace and electron beam cold bed furnace smelting. Electron beam cold-hearth melting has many advantages over vacuum arc melting:

1 Various forms of raw materials such as residual materials, loose titanium sponge and titanium shavings, and economical raw materials can be used;

2 It can remove high-density impurities such as molybdenum (Mo), tungsten (W) and tantalum (Ta), low-density impurities such as cyanide and volatile impurities, and is an important technology for pure titanium alloy materials;

3 Improve the yield of metals by producing ingots of various cross-sections.

Information from Stanford Advanced Materials (SAM) Corporation, a global sputtering target manufacturing company.

Multiple Applications of Silver

Medical uses of silver

Silver is used in many medical applications due to its antibacterial properties. Most medical devices, such as bandages, wound cleansers, catheters, pacemakers, valves and feeding tubes, that comes into contact with the body contain silver. The hospital also uses silver in air ducts to prevent certain conditions, such as Legionnaires Disease.

Silver for textiles

The thermal and biological properties of silver make it an ideal choice for the commercial textile industry. Silver is used in the anti-microbial properties of high-end sportswear to inhibit the growth of bacteria that can cause odors. Traditionally, silver and gold threads have been woven into clothing.

silver-for-textiles

Silver for food and water

Silver will play an important role in the food industry in the next decade. The US Food and Drug Administration has approved the addition of silver to bottled water to help kill bacteria, which opened the door for major municipalities to use white water for clean water at local communities, cities and state levels. Silver tip cutting tools are used for meat processing. It is also used in the processing of milk, cheese making and baking.

Silver superconductor

Another important use of silver is as a superconductor, mainly for large industrial and military electric motors. For a while, silver was used as a strategic reserve for military applications.

Other applications of silver

In addition to the above aspects, silver has many other uses. Silver is used as a wood preservative. Silver sputtering targets and silver evaporating materials are used for vacuum coating. The silver coating plays a key role in the solar power industry. Solar cells coated with silver absorb light and convert it into electricity.

silver-sputtering-coating

From the perspective of industrial applications, the future of silver is indeed very obvious. Many industrial applications will continue to use silver, and many new applications for silver will continue to grow at a significant rate.

Please visit https://www.sputtertargets.net/ for more information.

Molybdenum Application for Metallurgy

Molybdenum, a silvery-grey metal, does not seem to be as popular as tit anium, aluminum, and platinum. But it is actually a very widely used metal in our life. Today, we will introduce the application of molybdenum in metallurgy.

molybdenum-application-in-metallurgy
Molybdenum in Metallurgy

Steel Metallurgy

The main use of molybdenum for metallurgy is to produce various types of steel and alloys. The addition of molybdenum (mainly in the form of ferromolybdenum, molybdenum oxide, and calcium molybdate) to a range of steels such as structural steel, spring steel, bearing steel, tool steel, stainless steel, and magnetic steel can significantly improve the properties of steel.

Functions

Molybdenum improves the hardenability, toughness and heat strength of steel and prevents temper brittleness. It also improves the corrosion resistance of steel to certain media so that it does not pit. In addition, adding molybdenum into the cast iron enhances the strength and wear resistance of the cast iron.

Nonferrous Metallurgy

In non-ferrous metal alloys, molybdenum can be alloyed with metals such as nickel, cobalt, ruthenium, aluminum, and titanium. These molybdenum alloys are used in the electronics, electrical industry, and machinery industries to make filament and tube parts for light bulbs; they can also be used to make parts such as electromagnetic contacts, gas engine blades, valve protection, and electric furnace resistance.

nickel molybdenum alloy
Nickel Molybdenum Alloy
Functions

Molybdenum can improve the heat resistance and corrosion resistance of non-ferrous alloys and is an important element of nonferrous metallurgy.

Metal Processing

Molybdenum and its alloys can be used in a variety of molds, cores, perforated bars, tool holders and chill plates for metalworking.

Functions

Tools made of molybdenum can improve the processing speed and feed rate of metal processing, reduce the wear and deformation of metal parts, and thus extend the service life of the workpiece. These tools can also be used to machine large-sized parts and improve the accuracy of the workpiece.

Resistance welding electrodes made of molybdenum can be used for electronic brazing and welding of copper, brass and other materials with high thermal conductivity.

The molybdenum tip has a long service life and does not contaminate the workpiece, so it is suitable for processing electronic products.

Molybdenum can be used to make test dies for steel samples, which is very durable.

In addition, some metals require high temperature treatment in hydrogen, inert gas or vacuum, and molybdenum boats are ideal containers for holding such metals.

Molybdenum Boat
Molybdenum Boat

SAM Sputter Targets Corporation is a global evaporation material and sputtering target manufacturing company. Please visit https://www.sputtertargets.net/ for more information.

Working Mechanism of Pulsed Laser Deposition

Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique where a high-power pulsed laser beam is focused inside a vacuum chamber to strike a target of the material that is to be deposited.  Although the equipment of pulsed laser deposition (PLD) system is simple, its working mechanism is related to many complicated physical phenomena. It includes all physical interactions between the laser and the substance when the high-energy pulsed radiation strikes the solid sputtering target, the formation of plasma plumes and the transfer of the molten material through the plasma plume to the surface of the heated substrate. Therefore, PLD can generally be divided into the following three stages:

Interaction between laser radiation and the sputtering target

In this stage, the laser beam is focused on the surface of the target materials. When sufficient high energy flux and short pulse width are achieved, all elements of the target surface are rapidly heated to the evaporation temperature. At this point, the material in the target will be sputtered from the target. The instantaneous melting rate of the target is highly dependent on the flow of laser light onto the target. The melting mechanism involves many complex physical phenomena such as collisions, heat, excitation with electrons, delamination, and fluid mechanics.

Dynamics of molten matter

In the second stage, according to the law of aerodynamics, the sputtered particles have a tendency to move toward the substrate. The space thickness varies with the function cosn θ, and n>>1. The area of the laser spot and the temperature of the plasma have an important influence on the uniformity of the deposited film. The distance between the target and the substrate is another factor that affects the angular extent of the molten material. It has also been found that placing a baffle close to the substrate narrows the angular extent.

Deposition of molten material on the substrate

The third stage is the key to determining the quality of the film. The high-energy nuclides emitted hit the surface of the substrate and may cause various damages to the substrate. The high energy nuclide sputters some of the atoms on the surface, and a collision zone is established between the incident stream and the sputtered atoms. The film is formed immediately after the formation of this thermal energy zone (collision zone), which is the best place to condense particles. As long as the condensation rate is higher than the release rate of the sputtered particles, the heat balance condition can be quickly reached, and the film can be formed on the surface of the substrate due to the weakened flow of the molten particles.

The original text is from https://samsputtertargets.blogspot.com/.

Please visit https://www.sputtertargets.net/ for more information.

Holmium Oxide Introduction (Properties & Applications)

Overview

Holmium oxide is a chemical compound of rare-earth element holmium and oxygen with the formula Ho2O3. Together with dysprosium oxide, it is considered one of the most paramagnetic substances known. Holmium oxide is one of the constituents of erbium oxide minerals. In the natural state, holmium oxide often coexists with trivalent oxides of lanthanides, and we need special methods to separate them. Holmium oxide can be used to prepare a glass of a particular color. The visible absorption spectrum of Ho2O3-containing glasses and solutions has a series of sharp peaks and is therefore traditionally used as a standard for spectroscopic calibration.

Properties

Appearance  Light yellow or yellow powder, belonging to the equiaxed crystal yttria type structure
Density (g/mL, 25 ° C)  8.16
Melting point (° C)  2415
Boiling point (° C, atmospheric pressure)  3900
Solubility  insoluble in water, soluble in acid
Chemical reaction  Ho2O3+ 6 NH4Cl → 2 HoCl3+ 6 NH3+ 3 H2O

Applications

It is used to manufacture new light source xenon lamps, and can also be used as an additive for yttrium iron obtained from yttrium aluminum garnet and to prepare metal holmium. Holmium oxide can be used as a yellow and red colorant for Soviet diamonds and glass. Glass containing holmium oxide and holmium oxide solution (often perchloric acid solution) have sharp absorption peaks in the spectrum of 200-900 nm, and thus can be used as a standard for spectrometer calibration and have been commercialized. Like other rare earth elements, cerium oxide is also used as a special catalyst, phosphor, laser and coating material (sputtering targets & evaporation materials).

Holmium Oxide (Ho2O3) Sputtering Target

Holmium oxide sputtering targets

Holmium oxide sputtering targets with the highest quality can be used in semiconductor, chemical vapor deposition (CVD) and physical vapor deposition (PVD) applications. Stanford Advanced Materials (SAM) Sputtering Target Manufacturer offers target bonding service, reclaim service and customized service, which can help you make full use of the coating materials.

Please visit https://www.sputtertargets.net/ for more information.

Gadolinium Oxide Products (Powder & Coating Materials & Microcrystal )

Rare earth oxides (REOs) have gained more and more attention due to their unique magnetic, luminescent, and electrochemical properties. They are used for applications in various industries such as nuclear, electronics, lasers, and etc. Among them, although Gadolinium oxide (Gd2O3) is not the most widely used REOs, but is the most researched one.

The key property of Gadolinium Oxide

Chemical formula Gd2O3
Molar mass 362.50 g/mol
Magnetic susceptibility +53,200·10−6 cm3/mol
Density 7.41 (g/cm3)
Melting Point 2330  (°C)

Gadolinium oxide preparation

Gadolinium oxide can be formed by thermal decomposition of the hydroxide, nitrate, carbonate, or oxalates. Specifically, first, use monazite or a mixed rare earth ore as the raw material. Then Extract and purify the ore to prepare the samarium-gadolinium mixed rare earth solution. Use oxalic acid to precipitate gadolinium oxalic acid. Then separate, dry, and burn the gadolinium oxalic acid to obtain gadolinium oxide.

Gadolinium oxide powder

Gadolinium oxide is a white powder. It is insoluble in water but soluble in acid. It easily absorbs moisture and carbon dioxide from the air. It can be used as a raw material for various fluorescent compounds, absorption material in atomic reactions, nuclear fuels, magnetic bubble material, screen-sensitivity increasing material, as well as many other applications in the chemical, glass and electronic industries.

Gadolinium Oxide (Gd2O3) Powder
Gadolinium Oxide (Gd2O3) Powder

Gadolinium oxide sputtering target

Gadolinium oxide sputtering target is the product made of gadolinium oxide materials by casting or powder metallurgy. Common shapes of the gadolinium oxide sputter targets are planar, circular, rotary, and rectangular. In general, planar targets are cheaper but rotary targets have a higher utilization rate. Gadolinium oxide sputtering target is specially used in the sputtering process (a method of physical vapor deposition) to form a film on the substrate of glass, metal or other materials. Its purpose is either to protect the substrate or improve its properties.

Gadolinium Oxide (Gd2O3) Sputtering Target
Gadolinium Oxide (Gd2O3) Sputtering Target

Gadolinium oxide microcrystal

Gadolinium oxide microcrystal is defined as the gadolinium oxide nanomaterial with at least one direction usually in the range of 1–100 nm. These materials have different physical, chemical, and electrical properties in comparison with traditional bulk gadolinium oxide materials. These nanomaterials have the crystallographic stability up to temperatures of 2325°C, high mechanical strength, excellent thermal conductivity, and a wide band optical gap. Thus, they are used for new products and applications and may also be incorporated into various industrial processes in the nuclear industry, electronics, lasers, and optical material.

Gadolinium Oxide (Gd2O3) Nanomaterial
Gadolinium Oxide (Gd2O3) Nanomaterial

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Who discovered Iridium? | History of Metal

 

Iridium, a very hard, brittle, silvery-white transition metal of the platinum group, is the second-densest metal (after osmium) with a density of 22.56 g/cm3 as defined by experimental X-ray crystallography.

Iridium

Discovery

Smithson Tennant

Smithson TennantIridium was discovered together with osmium in1803 by English chemist Smithson Tennant in London. When crude platinum was dissolved in dilute aqua regia (a mixture of nitric and hydrochloric acids), it left behind a black residue. Because of the black color, it was initially thought to be graphite. By treating it alternately with alkalis and acids, Tennant was able to separate it into two new elements. These he announced at the Royal Institution in London, naming one iridium (comeing from the Latin word ‘iris’, meaning rainbow) because many of its salts were so colorful; and the other osmium (derived from osme, the Greek word for smell) because it had a curious odor.

Specification

Name Iridium
Symbol Ir
Color silvery-white
CAS number 7439-88-5
Melting point 2446°C, 4435°F, 2719 K
Boiling point 4428°C, 8002°F, 4701 K
Density (g cm−3) 22.5622

Feature

Iridium is a rare, hard, lustrous, brittle, very dense platinum-like metal. Chemically it is almost as unreactive as gold. It is the most corrosion-resistant metal known and it resists attack by any acid. Iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser.

Application

Due to its good corrosion-resistance, it is used of as a hardening agent for special alloy or to form an alloy with osmium, which is used for bearing compass and tipping pens.

Iridium Application

Iridium is used in making Iridium crucibles and other equipment that is used at high temperatures. Iridium sputtering target is a coating material to produce Iridium film, which is used as protective film or heavy-duty electrical contacts. In addition, Iridium was used in making the international standard kilogram, which is an alloy of 90% platinum and 10% iridium.

Please visit https://www.sputtertargets.net/ for more information.

 

Reference: “Iridium.” Chemicool Periodic Table. Chemicool.com. 17 Oct. 2012. Web. 3/21/2019 <https://www.chemicool.com/elements/iridium.html>.

Planar Sputtering Target: Pros and Cons

Although the rotary targets have developed in recent years, the mainstream shape of the sputtering target is still the planar type. Today let us take a look at the pros and cons of planar targets to help you determine whether a planar sputtering target is suitable for your project.

Advantages of Planar Sputter Target

Simple structure – one of the main advantages of the planar target is that the structure is simple. The common planar targets on the market are rectangular planar targets and circular planar targets, which are easily produced by molds. In other words, planar target preparation requires fewer machines and technologies and is easier to prepare. This is why planar targets still dominate the sputtering target market.

Planar sputtering target mould
Molds

Low price – You can never deny that the price is always an important competitive factor. As mentioned above, the manufacturing process of the planar sputter target is easier, so its price is much lower than the rotatory sputter target.

Strong versatility – Planar sputtering targets usually have strong versatility. Therefore, the transportation of the planar targets is relatively simple and is not easily damaged during transportation.

Good uniformity and repeatability – Film layers sputtered by planar targets usually boast good uniformity and repeatability. Planar targets are still best suited for prototype work or elemental experimentation, especially when large amounts of material are not needed at once.

Disadvantages of Planar Sputter Target

Its biggest disadvantage is the low utilization rate (generally only about 20%).  In the sputtering process of the planar target,  a strip-shaped pit will be formed when the target of the glow region (the magnetic field distribution region) is consumed to a certain extent, making the target body thinner. And once the pit depth reaches a certain value, the target cannot be utilized anymore. The low utilization rate also reduces its price advantage to some extent.

In conclusion, planar targets are still the best choice for prototype work or elemental experimentation, especially when large amounts of material are not needed at once. But its disadvantage of low utilization rate (20% vs. 80% compared with the rotatory target) does constrain its development.

Next week, let us look at the biggest competitor of the planar target– the rotatory target. Weighting the pros and cons of these two types of sputtering target may help you better choose the one for your application.

Please visit https://www.sputtertargets.net/ for more information.

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.