Topic:

Glossary: E

Here you are going to find explications of important terms in plasma technology:

I,J

P,Q

X,Y,Z

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electric arc: There are arc discharges (ablation of electrodes, high currents) and spark discharges (electron avalanches through high electrical field strengths).
electrode: An electrode forms the contact to another medium (solid, liquid, gaseous) for the current passing.
electron: Negatively charged elementary particle (symbol: e; mass=9.1·10-31 kg; charge=-1.6·10-19 As). The atoms’ shell consists of electrons.
electron microscope (EM) / Scanning Electron Microscope (SEM): An electron microscope uses electrons instead of electromagnetic waves (microwave radiation, visible light, UV-radiation, x-rays) to display the sample surface. A microscope’s resolution depends on the wavelength. The shorter the wavelength the higher the resolution, that’s why the resolution of an EM is distinctly better (0.1 nm) than the one of a light-optical microscope (200nm). The electrons are generated by a cathode and then accelerated towards a ring-shaped anode that is situated around the axis of radiation. The electrons are directed by a system of magnetic or electrostatic lenses, analogously to the light-optical microscope, to the sample where they are scattered; adjacently they are registered by a detector. As molecules would scatter the electrons, it is necessary that the microscope is in vacuum. Due to the bombardment of the surface with charged particles, the sample has to be conductive and grounded in order to avoid charging effects.
electron volt: Energy unit (abbreviation: eV). The energy of an electron when it passes an accelerating voltage of 1 V. 1 eV = 1.6·10-19 J. 1 keV = 1.000 eV; 1 MeV = 1.000.000 eV.
electronegative plasma: Plasma with less electrons; not quasi-neutral.
electropositive plasma: Plasma with electron excess; not quasi-neutral. Consisting of cations and electrons mainly.
EPDM profiles: Ethylene propylene diene mixture (EPDM) is a black elastomer that is often used as sealing profile in the automobile industry. Through a pre-treatment, e.g. by radicals, charged and activated particles as those existing in plasma, the surface tension of a plastic can be increased so much that the material can be agglutinated, varnished, flocked, and supplied with waterbased anti-friction varnishes.
epitaxy: Ball-shaped crystal growth into open space. Defined relation between the crystallographic orientation of a substrate and a coating. Can be observed on PVD coatings on Si wafers.
ESCA: Electron Spectroscopy for Chemical Analysis, or IEE (Induced Electron Emission), resp. XP(E)S (X-Ray induced Photoelectron Spectroscopy. Allows the analysis of binding states, especially used for the analysis of sample surfaces (e.g. for the determination of oxidation states, where all elements except for hydrogen and helium can be analysed).
etching: The process of etching uses solvents to generate little cavities in the surfaces of various bodies. If the treated body is not totally homogeneous, then certain parts corrode more excessively and patterns are formed which reveal the original structure of seemingly homogeneous bodies; occasionally such patterns are generated intentionally for purposes of decoration (damascening, moiré métallique). If individual parts of the surface are protected by a material (etching ground or strippable coating), that does not get affected by the caustic agent, then any pattern can be produced at will. For example, the entire surface is covered with etching ground, then the pattern is scratched onto the ground with suitable needles and styles; next, the area to be treated is surrounded by a raised border (usually made of wax) that is resistant to the corrosive substance. Finally, a liquid (usually an acid one) is poured onto the area which takes a dissolving effect on the parts of the surfaces that were uncovered by the needles/styles. The result is an engraved representation of the pattern. (see "engraving").
etching circuit boards: see "etching PCBs"
etching PCBs: Via plasma, boreholes are reetched and organic coating residues removed from the lithograph.
etching PTFE: see "etching Teflon"
etching Teflon: Etching is obtained through a chemical reaction of a sodium dilution with the fluorine molecules on the Teflon’s surface. The fluorine molecules are detached from the fluorine frame of the fluorine polymer. This way, the carbon atoms are lacking electrons. When the etched material is then exposed to the air, oxygen molecules, steam, and hydrogen facilitate reconstitution of the electrons. This reconstitution process in a group of organic molecules is responsible for adhesion. A simple and environmentally gentle possibility is a surface treatment by plasma. It makes it possible to give the normally hydrophilic material Teflon hydrophobic properties and enable thus adhesion.