Plasma Glossary online

Adhesion refers to the forces of adhesion at the contact surfaces between two different or identical materials, which are caused by molecular forces.

AIF stands for the “Otto von Guericke” Association of Industrial Research Organizations.

A treatment for wool fibers that prevents them from matting during the washing process.

A high-temperature-resistant, non-flammable, high-strength synthetic fiber made from aromatic polyamides (brand names: Nomex, Kevlar), with a decomposition temperature of approximately 400 degrees Celsius. These fibers are best known for their use in bulletproof vests, protective helmets, and vehicle armor.

A special form of plasma that forms between two electrodes with a sufficiently high voltage difference. Electric arcs are used in engineering as light sources, in high-voltage switches, and in plasma cutting and welding.

The compatibility between materials used in medicine and living organisms. This is particularly important in the case of implants.

BMB = Bundesministerium für Bildung und Forschung
BMWA = Bundesministerium für Wirtschaft und Arbeit

Coatings made of diamond-like carbon (see DLC) that reduce wear on parts subjected to high mechanical stress (e.g., bearings, valve heads in engines).

Fibers made from cellulose, modeled after the structural material of plants (e.g., cotton, linen, paper fibers). Chemically, cellulose is a polysaccharide.

The Chlor-Hercosett process is a wet chemical process for the anti-felting treatment of wool using chlorine and polyaminoamide.

Plasma coating: The process of depositing a layer of material onto a workpiece by causing previously vaporized material to condense under the influence of a plasma.

A solution in which a substance is very finely dispersed in a solvent. Both the colloid and the solvent can be a solid, a liquid, or a gas.

A plasma-based process performed at atmospheric pressure based on the DBD principle, which is frequently used to modify the wetting behavior of materials.

DBD = Dieletric Barrier Discharge or dielectric barrier discharge. Plasma is generated using two metal electrodes to which an alternating voltage is applied, with an insulating material placed between them. As a result of the discharge at atmospheric pressure, a plasma forms in the space between one of the electrodes and the insulating material.

A general term for measurement methods used to determine key parameters of plasmas (e.g., electron density, electrode temperature, degree of ionization). Common methods include: the plasma probe (Langmuir probe), optical spectroscopy, infrared laser absorption spectroscopy, and microwave interferometry.

The ratio of the number of ions in a plasma to the sum of neutral atoms or molecules and ions. The degree of ionization is an important parameter for plasmas.

DiamondLike Carbon. Layers of carbon that resemble diamond in terms of hardness and surface properties.

Rubbery materials composed of highly cross-linked molecules (e.g., natural rubber and polyurethanes).

Number of free electrons in a unit volume. Expressed in electrons per cubic centimeter. One of the most important parameters for a plasma. Other parameters include: electron temperature and degree of ionization.

Average kinetic energy of the free electrons in a plasma. Expressed in kelvins (K) or electronvolts (eV).

Material removal achieved either using acids (wet chemical etching) or via ions or radicals from a plasma (dry etching). Etching processes play a major role in microstructuring, as they ensure the necessary dimensional accuracy for the structural dimensions to be produced. Classification of the repellent or accepting behavior of surfaces toward liquids (hydrophilic, hydrophobic, and oleophobic).

High-intensity light sources in the so-called extreme UV range (wavelength: up to 13 nanometers) for the manufacture (lithography) of microchips.

Plasma fine cleaning: A process step used to clean surfaces. Its primary application is the removal of organic contaminants (oils) and oxides from metal surfaces. Plasma fine cleaning uses O2/Ar, H2O, or Ar/H2 plasmas for this purpose.

Ferroelectricity refers to the emergence of a preferred direction in a material along which the material’s elementary electric dipoles align. This material property is exploited, for example, in ferroelectric ceramics, which can either be deformed by applying an electric field or generate an electric voltage when subjected to pressure (pressure sensors).

A fuel cell is an energy converter that directly converts stored chemical energy into electrical energy.

A process for applying functional chemical groups to a surface. These chemical groups can be used to modify the properties (e.g., wetting behavior) of the treated surfaces. Unlike activation, functionalization prepares the surface for specific (selective) reactions.

A thermal plasma used to generate energy through the fusion of hydrogen and deuterium atoms into helium.

Also: Plasma light generation using a gas discharge lamp. A light source in which a plasma is generated by an electric current, causing it to glow. The most common type of gas discharge light source is the fluorescent tube.

A gas discharge that occurs at low pressure (a few thousandths of atmospheric pressure) and low gas temperatures (a few hundred kelvins). Glow discharges are used, among other things, to generate light (gas discharge light source).

Fibrous materials with a molecular structure similar to that of graphite. They exhibit high resistance to heat and corrosion, as well as high tensile strength.

A plasma source that generates a plasma in a gas at low pressure using high-frequency electromagnetic radiation. Common frequencies are 13.56 MHz and 2.45 GHz. RF plasma sources are used in virtually all areas of plasma technology (e.g., plasma coating, etching, activation, and functionalization).

Frequency range of an electric and/or magnetic field from 10 kHz to 300 GHz.

A technology that involves the generation of very short (millisecond to nanosecond) electrical pulses, often with high energy (100 terawatts). The pulses are mainly used for material processing (e.g., breaking up rocks).

Light sources that use an electric arc to produce light. The arc burns between two electrodes inside a glass container at a pressure of 10 to 100 atmospheres. Xenon is typically used as the gas.

A fuel cell that operates at an operating temperature of 550–1000°C.

Plasma switches: Devices used to switch currents at voltages ranging from 50 to 150 kV. The switching process is driven by a plasma that burns as an arc between the switch’s electrodes until the process is complete. Such switches are also referred to as plasma switches.

An electron source consisting of a metal wire that is heated to incandescence by an applied electrical voltage (approximately 25 volts). This causes electrons to be emitted from the metal. They are used in gas-discharge light sources and cathode-ray tubes.

Synthesis of C2H2 from methane using a plasma arc. The arc burns between two electrodes at a voltage of 7 kV and a power of 8 MW.

Greek for “loving water.” Hydrophilic surfaces exhibit good wettability when exposed to water (see wetting behavior). This property determines whether a surface can be treated with water-soluble coatings.

A term referring to an HF plasma source in which electromagnetic radiation is coupled into the plasma via a coil located outside the plasma reactor. Compared to methods in which electrical energy is coupled into the plasma via two electrodes extending into it, the inductive method has the advantage that there is no wear on the electrodes due to electron or ion bombardment.

Measurement methods for determining the composition and temperature of gases and plasmas (see Diagnostics).

The energy of a body that cannot be altered by moving the body as a whole. An example is the temperature of a body, which is the average kinetic energy of its atoms.

The Latin term “in situ” means “on site.” Accordingly, in situ diagnostics of a process involves taking measurements “on site,” i.e., within the process equipment. Controlling a process using in situ diagnostics is therefore referred to as in situ control.

A process in which electrons are either removed from or added to atoms or molecules. As a result, the previously electrically neutral atom or molecule becomes positively or negatively charged.

A pressure range of about one millionth of atmospheric pressure (10-3 mbar).

The technical term “LASER” is an acronym for: Light Amplification by Stimulated Emission of Radiation.
In German: Lichtverstärkung durch angeregte Strahlungsaussendung. A laser is a light source that emits very intense, monochromatic light.

A spectroscopic measurement in which a laser is used as a light source to excite atoms and molecules.

LED stands for Light Emitting Diode.
German: Leuchtdiode.
An electronic component made of semiconducting, inorganic materials that emits monochromatic light.

A gas-discharge light source that uses a glow discharge to produce light.

A plasma in which the temperature of the ions and neutral atoms does not exceed a few hundred kelvins, while the electron temperature is several hundred thousand kelvins. Glow discharge is a typical example.

A measure of the efficiency of an electric light source. It indicates the ratio between the luminous flux (lumens) emitted by the source and the electrical power (watts) required to produce it. Incandescent bulbs have an efficiency of approximately 10 lumens per watt, while gas-discharge light sources achieve an efficiency of up to 100 lumens per watt. The highest lumen output is currently achieved by HID lamps at 120 lumens per watt—

An integrated electronic circuit made of semiconductor materials (primarily silicon). Today, most microchips contain millions to billions of transistors, depending on the chip type and year of manufacture.

The production of structures with characteristic lengths of less than one millimeter. This process is primarily used in microelectronics.

The generation of a plasma in which electrical energy is coupled into a gas in the form of microwave radiation.

Switches designed for electrical voltages ranging from 10 to 50 kV. As with high-voltage switches, the switching process is driven by an electric arc. Medium-voltage switches are a type of plasma switch.

Molecules containing a reactive double bond or functional groups. These can react with one another to form long-chain molecules known as polymers. A commonly used polymer is polyethylene (e.g., packaging films). The monomer used here is the ethylene molecule C2H4. Ethylene is a gaseous substance derived from petroleum or natural gas.

Fibers with diameters significantly less than one micrometer (one-thousandth of a millimeter). Carbon-based nanofibers (carbon nanotubes) exhibit high stiffness combined with low weight, as well as high thermal conductivity. Furthermore, these fibers possess electrical conductivity ranging from metallic to semiconducting. Potential applications for such fibers include sensor technology, optics, electronics, and the textile industry, as well as materials for automobiles and aircraft.

A composite material in which at least one component is present in the form of particles with diameters of less than one micrometer (one-thousandth of a millimeter). Nanocomposites are colloidal systems.

A specific type of carbon nanotube in which layers of carbon atoms are arranged concentrically, like the layers of an onion.

A particle with a diameter of less than one-thousandth of a millimeter. In extreme cases, they consist of a few hundred atoms of a single element. The potential applications of these particles range from use in composite materials (nanocomposites) to pharmaceuticals (e.g., crossing the blood-brain barrier).

Creation of structures in the submicrometer range (less than one-thousandth of a millimeter).

A closed arrangement of atoms in a network along the surface of a cylinder. The best-known examples are so-called carbon nanotubes, which have a diameter of about one nanometer (one-thousandth of a micrometer) and lengths of up to one millimeter.

A plasma in which the temperatures of the electrons, ions, and neutral atoms are not the same. Example: low-temperature plasma.

Plasma nitriding: The process of diffusing nitrogen into a metal workpiece to increase the surface hardness. During plasma nitriding, the workpiece is electrically charged with a negative charge and placed in a nitrogen plasma. The positively charged nitrogen ions strike the surface with high energy and penetrate the workpiece.

A term used for nonwoven textiles (e.g., felts, fiber composites, needle-punched felts); a general term for textile composites that are consolidated mechanically or through physical-chemical processes.

OLED = Organic lightemitting diode
An LED in which the semiconductor material is made of organic compounds.

Greek for “oil-repellent.” Surfaces with oleophobic properties do not absorb oil (see wetting behavior).

A branch of electronics that utilizes the interactions between electric charge carriers and light particles (photons) for the generation, transmission, processing, and storage of information.

Investigation of the motion of particles under internal and external influences.

Direct conversion of sunlight into electrical energy using solar cells.

Plasma explained simply and briefly: In physics, a partially or fully ionized gas (degree of ionization) containing free charge carriers such as ions, atomic nuclei, or electrons.

A region near the walls that confine a plasma. In this region, the density of positive and negative charge carriers is not balanced, as is usually the case in a plasma.

A process in which plasma is used as a material converter. A distinction is made between thermal and non-thermal plasma chemistry. In thermal plasma chemistry, the energy required for the material conversion is derived from a thermal plasma (e.g., the Hüls process). Non-thermal plasma chemistry primarily utilizes the energy of the electrons in a non-thermal plasma (low-temperature plasma).

Chemical processes initiated by a plasma.

A material conversion process that utilizes a combination of plasma-chemical processes and catalytic reactions.

A material processing method for cutting and joining (welding) using an electric arc.

A screen on which the pixels are generated by a dielectric barrier discharge (DBD). The three primary colors (red, green, blue) are produced using dyes.

Applications and processes in which plasmas are used as a direct working medium. Examples: plasma coating, plasma cutting and welding, plasma nitriding.

Effects that occur when electrons, ions, excited atoms or molecules, or light radiation from a plasma strike a surface. Examples include the ejection of surface atoms by high-energy ions (ion sputtering) or the deposition of low-energy ions onto the surface (plasma coating).

An electrical device used to generate a plasma. In this process, the energy of electromagnetic fields is coupled into a gas in such a way that it becomes ionized (see ionization) and forms a plasma.

A coating process in which the coating material, in powder form, is blown into a plasma jet. The powder melts in the plasma jet and deposits as a layer on the workpiece, which is fed into the plasma jet.

A method for killing pathogens. The process works by exposing the surface to be disinfected to a plasma.

A special case of plasma-surface interaction in which the effects of the plasma on the wall material of a plasma chamber are studied. These interactions are of particular importance in fusion reactors (see fusion plasma).

Application of scientific findings in chemistry and physics to large-scale industrial processes.

The frequency at which, for example, a laser pulse is repeated. The term is mainly used when the duration of a pulse is much shorter than the interval between pulses.

A polymer material that behaves as desired in response to external influences.

Sintered materials: Materials made from a powder that is typically heated and pressed under pressure to form a solid.

A substrate is typically a thin single-crystal wafer made of semiconductor material with a defined crystal orientation. It serves as a base or foundation for the controlled growth of layers. Generally, the term refers to wafers made of any material that are used in a coating process.

A general term for all textiles that are not classified as clothing or home textiles. This includes, for example, conveyor belts, filter fabrics, medical textiles, textiles used as building materials, and protective clothing.

The tensile test is a standardized procedure for measuring tensile strength and other material properties.

A term used to describe a plasma produced by heating a gas to several hundred kelvins. Example: fusion plasma.

Properties of a mechanical component that play a role when subjected to friction. Specifically, these are: friction, wear, and lubrication.

A polymer in which ethylene is linked into chains with a molecular weight of up to one million. This material is used in the medical field for implants.

A layer that prevents certain substances from passing from one compartment to another. Example: Barrier layers in plastic beverage bottles that prevent carbon dioxide from escaping from the liquid through the bottle wall.

Greek for “water-repelling.” Surfaces with hydrophobic properties cause water to bead up and roll off (see wetting behavior).

The term for woven textiles (as opposed to nonwoven).