A’s
Abrasion the surface loss of a material due to frictional forces.
Absorption the penetration of matter in bulk into other matter, as in dissolving of a gas by a liquid.
Accelerator a compounding material used in small amounts with a vulcanizing agent to increase the speed of vulcanization.
Accelerator, delayed action an accelerator that, in conjunction with other curing agent(s), produces, at vulcanizing temperatures, a period of no significant cross-linking, followed by a period of rapid cross-link formation.
Accuracy a concept of exactness. When applied to a test method, it denotes the extent to which bias is absent; when applied to a measured value, it denotes the extent to which both bias and random error are absent.
Activator compounding material used in small proportions to increase the effectiveness of an accelerator.
Adhesion failure the loss of structural integrity due to the separation of two bonded surfaces at the bond interface.
Adsorption the surface retention of matter by other matter.
Agglomerate, latex a cluster of rubber particles in a colloidal aqueous suspension of such particles.
Agglomerates clusters of particles of compounding materials contained in a continuous rubber phase.
Aging(act of) exposure of materials to a deteriorating environment for a specified time interval.
Aging the irreversible change of material properties during exposure to a deteriorating environment for a specified time interval.
Aliphaticstraight-chain hydrocarbons. Three sub-groups are alkanes, alkenes, and alkynes.
Alloy a unique composition of two or more polymers that has one or more of the polymers treated or processed in a special way to confer enhanced performance characteristics on the resulting material.
Alpha particle a positively charged particle consisting of two protons and two neutrons.
Amorphous materials with no definite arrangement of atoms.
Ampere or Amp a unit of current””the rate at which electrons move past a reference point.
Angstrom (Ã) a unit of length, an angstrom is one ten-thousandth of a micron (10-4 µm) or 100,000,000 Ã =1 cm.
Anisotropic an etch process that exhibits little or no undercutting.
Anneal a high-temperature processing step, designed to minimize stress in the crystal structure of the wafer.
Anticoagulant a substance added to field latex to retard bacterial action which would otherwise cause rapid coagulation of the latex.
Antidegradant a compounding material used to retard deterioration caused by oxidation, ozone, light and combinations of these.
Anti-extrusion ring a thin ring installed on the lowpressure side of a seal to prevent elastomer extrusion into the clearance gap.
Antiflexcracking agent a compounding material used to retard cracking caused by cyclic deformations.
Antioxidant compounding material used to retard deterioration caused by oxidation.
Antiozonant compounding material used to retard deterioration caused by ozone.
Antistatic agent a material which reduces the tendency for accumulation of electric charge on the surface of an article.
Aromatic oil a hydrocarbon process oil containing at least 35%, by mass, of aromatic hydrocarbons.
Ash the residue from incineration of a material under specified conditions.
Ashing the process of removing photoresist with oxygen plasma.
Atmospheric-pressurechemical vapor deposition (APCVD) a method for depositing layers at atmospheric pressure.
Attenuation a reduction in intensity of energy traveling through a medium or space.
Autoclave a vessel used for vulcanizing rubber compounds by means of steam pressure.
B’s
Backrinding a molding defect in which the rubber adjacent to the flash line shrinks below the surface of the molded product, with the flash line often being ragged and torn.
Bake-out secondary post-curing operation designed to remove residual volatile materials.
Batch the product of one mixing operation.
Beta particle an electron or positron emitted from a nucleus.
Bipolar transistor a transistor (consisting of an emitter, base and collector) whose action depends on the injection of minority carriers from the base by the collector.
Blank a portion of a rubber compound of suitable volume to fill the cavity of a mold.
Bleeding the exuding of a liquid compounding material from the surface of a vulcanized or unvulcanized rubber.
Blister a cavity or sack that deforms the surface of a material.
Bloom a liquid or solid material that has migrated to the surface of a rubber and generally changes the surface appearance.
Blowing agent a compounding material used to produce gas by chemical or physical action, or both, in the manufacture of hollow or cellular articles.
Borophosphosilicate glass (BPSG) a compound of boron, phosphorus, silicon and oxygen.
Bound monomer monomer that is combined or reacted with itself or other types of monomers in a polymerization reaction to form a polymer.
Breakaway friction the force required to overcome friction to start a body in motion over a surface.
Brittle point the temperature at which elastomers break when subjected to an impact.
Bulk modulus of elasticity also known as compression modulus, the ratio of compressive force applied to a surface per unit surface area to the change in volume of the substance per unit volume.
Bumping, molding process the application, release, and reapplication of pressure prior to the start of vulcanization to vent entrapped gases, thereby facilitating complete filling of the mold.
Butt joint a connection made with two ends cut at right angles.
C’s
Calender a machine with two or more parallel, counterrotating rolls with a controllable, roll-to-roll spacing, rotating at selected surface speeds and controlled temperatures, used for sheeting, laminating, skim coating (topping) and friction coating, to a controlled thickness and/or surface condition.
Capacitor a discrete device which stores electrical charge on two conductors separated by a dielectric.
Cell a single small cavity surrounded partially or completely by walls.
Chalking the formation of a powdery residue on the surface of a rubber, commonly resulting from surface degradation.
Chamber clean typically, a gas or plasma cleaning of the chamber to prevent the buildup of polymer or contamination on the chamber walls.
Chemical vapor deposition(CVD) a method for depositing some of the layers which function as dielectrics, conductors or semiconductors. A chemical containing atoms of the material to be deposited reacts with another chemical, liberating the desired material, which deposits on the wafer while by-products of the reaction are removed from the reaction chamber.
Chemisorption a chemical adsorption process in which weak chemical bonds are formed between gas or liquid molecules and a solid surface.
Chip die or device, one of the individual integrated circuits or discrete devices on a wafer.
Coagent a compounding ingredient used in small amounts to increase the cross-linking efficiency of certain no-sulfur vulcanizing systems or to modify the properties given by such systems.
Coefficient of friction the force in the direction of motion required to move one surface with respect to another, divided by the force normal to the two surfaces.
Coefficient of thermal expansion the increment in volume of a unit volume of material for a rise of one degree temperature at constant pressure.
Cohesive failure a rupture occurring entirely within any single uniform layer of the assembly.
Cold flow slow deformation, under gravitational force, at or below room temperature.
Comonomer one of the two or more monomer species that polymerize to form a copolymer.
Complimentary metal oxide semiconductor (CMOS) N- and P-channel MOS transistors on the same chip.
Composite seal a seal composed of two or more dissimilar materials.
Compound an intimate admixture of a polymer(s) with all the materials necessary for the finished article.
Compression the amount of deformation on a seal, often calculated by dividing the deformation by the original seal cross-sectional diameter.
Compression molding molding process in which the material is placed directly in the mold cavity and compressed to shape by closure of the mold.
Compression set the residual deformation of a material after removal of the compressive stress.
Conditioning (environmental) the storage of a rubber, under specified conditions (time, temperature, humidity) prior to testing.
Conditioning (mechanical) the prescribed program of deformation of a specimen prior to testing.
Conductive rubber an elastomer having high conductivity. Conductor a material which is easily able to conduct electricity.
Copolymer a polymer formed from two different monomers. Covalent bonding chemical bonding whereby each atom of a bound pair contributes one electron to form a pair of electrons.
Crack(s), atmospheric fissure(s) originating in the surface of a rubber vulcanizate or product as a result of natural weathering.
Crack(s), ozone fissure(s) originating in the surface of a rubber vulcanizate, caused by exposure to an ozone-containing environment; the fissure(s) are perpendicular to the direction of strain.
Crack(s), flex fissure(s) originating in the surface of a rubber vulcanizate, resulting from cyclic deformation (usually bending).
Creep the time-dependent part of a strain resulting from stress.
Cross-link chemical bond bridging one polymer chain to another.
Cross-linking agent compounding material that produces cross-linking in rubber.
Crystallization, polymer arrangement of previously disordered polymer segments of repeating patterns into geometric symmetry.
Cure see vulcanization, the preferred term.
D’s
Decibel(dB) an expression of the ratio of two values of power or voltage in logarithmic terms.
Density the mass-per-unit volume of a material.
Deposition process in which layers are formed as the result of a chemical reaction in which the desired layer material is formed and coats the wafer surface.
Desiccant compounding material used to irreversibly absorb moisture present (in a rubber mix) particularly for the purpose of minimizing risk of porosity during vulcanization.
Developer chemical used to remove areas defined in the masking and exposure step of wafer fabrication.
Die swell difference between the dimensions of the cross section of an extrudate and the corresponding dimensions of the die orifice by which the extrudate is formed.
Dielectric a material that conducts no current when it has voltage across it.
Diene polymer a polymer formed from one or more monomer species, at least one of which is a diolefin.
Diffusion the spontaneous mixing of one substance with another when in contact with, or separated by, a permeable membrane or microporous barrier.
Diffusion a process used in semiconductor fabrication which introduces minute amounts of impurities (dopants) into a substrate material and permits the impurity to spread into the substrate. The process is very dependent on temperature and time.
Dipole a molecule with positive and negative charge centers.
Dispersing agent (latex) a surface-active substance used to facilitate the suspension of solid compounding materials in a liquid medium and to stabilize the dispersion thereby produced.
Dispersion (the act of) application of shearing forces to distribute one or more compounding materials uniformly throughout the mass of a continuum material.
Dopant an element that alters the conductivity of a semiconductor by contributing either a hole or electron to the conduction process. For silicon, the dopants are found in Groups III and V of the periodic table.
Doping the introduction of impurity atoms (dopants) into the crystal lattice of a semiconductor.
Dry etching a process resulting in the selective removal of material, achieved by the use of gas or plasma.
Dry-ox the growth of silicon dioxide using oxygen and hydrogen, which forms water vapor at process temperatures, rather than using water vapor directly.
Dumbbell specimen a flat specimen having a narrow, straight central portion of essentially uniform cross section.
Durometer an instrument for measuring the indentation hardness of rubber.
Dynamic random access memory (DRAM) memory device for the storage of digital information. The information is stored in a volatile state.
Dynamic seal a seal designed to prevent leakage between surfaces which move relative to each other.
E’s
Elastic limit the greatest stress that a material is capable of sustaining without any permanent strain remaining upon complete release of the stress.
Elastomer a viscoelastic macromolecular material that can respond to large deformations.
Electronegativity a material that has a tendency to attract electrons to itself.
Elongation the extension of a uniform section of a specimen expressed as percentage of the original length.
Elongation, ultimate the elongation at the time of rupture.
Emulsifying agent(latex) a surface-active substance used to facilitate the dispersion of an immiscible liquid compounding material in another liquid and to stabilize the emulsion thereby produced.
Epitaxial (Greek for arranged upon) the growth of a single-crystal semiconductor film upon a single-crystal substrate.
Erasable programmable read-only memory (EPROM) device that allows stored information to be erased; erasing is typically accomplished with ultraviolet light. Esters a compound formed by the elimination of water and the bonding of an alcohol and an organic acid.
Etch a process for removing material in a specified area through a wet or dry chemical reaction or by physical removal, such as a sputter etch.
Ethers a compound characterized by “-O-“ bonding
Evaporation a process step that uses heat to change a material (metal or metal alloy) from its solid state to a gaseous state with a result of the source being deposited on wafers. Both electron beam and filament evaporation are common in semiconductor fabrication.
Exposure method of defining patterns by the interaction of light or other form of energy with photoresist that is sensitive to the energy source.
Extender an organic material used to augment the polymer in a compound.
Extensometer a device for determining elongation of a specimen as it is strained.
Extrudate the material that issues from an extruder.
Extruder machine designed to force a rubber or rubber mix through an orifice, which is often shaped to the geometry of the desired product.
Extrusion 1) the continuous shaping of a material during plastic passage through a die. 2) the displacement of a part of the seal into the clearance gap under action of fluid pressure or thermal expansion.
F’s
Face seal, flange seal an axial contact seal.
Fatigue life(dynamic) the number of deformations required to produce a specified state of fatigue breakdown in a test piece or product that is deformed under a prescribed set of conditions.
Field oxide the region on an electrical device where the oxide serves the function of a dielectric.
Field-effect transistor (FET) a transistor consisting of a source, gate and drain, whose action depends on the flow of majority carriers past the gate from the source to the drain. The flow is controlled by the transverse electric field under the gate.
Filler a solid compounding material, usually in finely divided form, which may be added in relatively large proportions to a polymer for technical or economic reasons.
Fissure a surface split or crack.
Flash the excess material protruding from the surface of a molded article at the mold junctions.
Flex life the number of cycles required to produce a specified state of failure in a specimen that is flexed in a prescribed method.
Flow a process step in which the wafer temperature is elevated so that the deposited PSG or BPSG surface layer’s topography smoothes out due to the film’s low viscosity at elevated temperatures. The flow temperature is primarily dependent on incorporation of the dopant.
Flow marks marks or lines on a molded product, caused by imperfect fusion or “knitting” of material.
Fluorocarbon elastomer also known as fluoroelastomer.
Fluorosilicone a fluorinated silicone elastomer.
Foam stabilizer (latex) a substance used in the preparation of latex foam to help stabilize the foam latex before gelation, drying and vulcanization.
Formula a list of the materials and their amounts used in the preparation of a compound.
Frequency the number of periodic oscillations, vibrations or waves per unit of time.
Furnace a piece of equipment containing a resistanceheated element and a temperature controller. It is used to maintain a region of constant temperature with a controlled atmosphere for the processing of semiconductor devices.
Furnace carbon black type of carbon black produced by the decomposition reaction of hydrocarbons when injected into a high-velocity stream of combustion gases under controlled conditions.
G’s
Gallium arsenide (GaAs) a semiconductor material with the advantage of producing radiation-resistant and higherspeed devices than those produced using silicon as a substrate.
Gamma radiation the emission of high-energy photons.
Gasket a deformable material clamped between essentially stationary faces to prevent the passage of matter through an opening or joint.
Gate oxide a thin, high-quality silicon dioxide film that causes the induction of charge, creating a channel between source and drain regions of an MOS transistor.
Gel, dry rubber the portion of unvulcanized rubber insoluble in a chosen solvent.
Gland a cavity into which a seal is installed.
Grain anisotropy introduced into rubber during processing operations.
Gum compound a rubber compound containing only those ingredients necessary for vulcanization and small amounts of other ingredients for processing, coloring and improving the resistance to aging.
H’s
Hardness a material’s ability to resist a distorting force (indentor point).
Heat buildup the accumulation of thermal energy generated within a material as a result of hysteresis, evidenced by an increase in temperature.
Hertz (Hz) an international unit for frequency””the number of cycles per second.
Hole the absence of a valence electron in a semiconductor crystal. Motion of a hole is equivalent to motion of a positive charge.
Homogeneous having uniform composition or structure.
Homogenization repeated passage of raw rubber through a mill or other mixing device, under specified conditions, to ensure uniformity.
Homopolymer a polymer formed from a single monomer species.
Hybrid integrated circuit a structure consisting of an assembly of one or more semiconductor devices and a thin-film integrated circuit on a single substrate, usually ceramic.
Hydrogen bonding unusually strong dipole-dipole attractions that occur among molecules in which hydrogen is bonded to a highly electronegative atom.
Hydrophilic affinity toward water (water-loving); a hydrophilic surface is one that will allow water to spread across it in large puddles.
Hydrophobic aversion to water; a hydrophobic surface will not allow large puddles of water, but rather will form droplets. These surfaces are often termed “de-wetted.”
Hydroscopic attracts and absorbs water.
Hysteresis the lagging of strain behind stress during deformation.
I’s
Impact resistance resistance to fracture under shock force. Impedance the total opposition offered by an electric circuit to the flow of an alternating current. It is the combination of resistance and reactance.
In situ Refers to the sequential process steps that can be completed without removing the wafers from one process environment to another.
Inhibitor a material used to suppress a chemical reaction.
Integrated circuit (IC) a circuit in which many elements are fabricated and interconnected on a single chip of semiconductor material.
Interlayer dielectric (ILD) films that insulate between the wafer surface and the first metal layer. They are typically some form of doped silicon dioxide, formed by reaction between a silicon source gas (silane or TEOS), an oxidizing gas (O2, N2) and dopant source gases.
Intermetal dielectric (IMD) films that insulate between two layers of conductive metal.
Ion an atom that has either gained or lost electrons, making it a charged particle.
Ion implantation introduction of selected impurities (dopants) by means of high-voltage ion bombardment to achieve desired electronic properties in defined areas.
Ionic bonding the electrostatic attraction between oppositely charged ions””characterized by electron transfer.
Isotactic a polymeric molecular structure containing a sequence of regularly spaced asymmetric atoms arranged in like configuration in the polymer chain.
Isotropic having the same properties in all directions.
K’s
Ketone an organic compound containing the carbonyl group -C=O.
Kinetic friction the minimum force required to maintain a body in motion over a surface.
L’s
Latex colloidal aqueous dispersion of rubber.
Light-emitting diode (LED) a semiconductor device in which the energy of minority carriers in combining with holes is converted to light.
Lip seal a custom seal, static or dynamic, that seals on a flexible extension.
Lithography process of pattern transfer; when light is utilized, it is termed photolithography and when patterns are small enough to be measured in microns, it is referred to as microlithography.
Lot a mass of material or collection of articles of similar composition and characteristics.
Low-pressure chemical vapor deposition (LPCVD) system with the deposition environment less than atmospheric pressure. Most LPCVD systems use a quartz boat (wafer holder) placed in a furnace which is brought up to deposition temperature.
M’s
Mask a glass plate covered with an array of patterns used in the photomasking process. Mask patterns may be formed in emulsion, chrome, iron oxide, silicon or a number of other opaque materials.
Masterbatch a homogeneous mixture of rubber and one or more materials in known proportions for use as a raw material in the preparation of the final compounds.
Mastication a breakdown or softening of raw rubber, or a mix, by the combined action of mechanical work (shear) and atmospheric oxygen, sometimes accelerated by the use of a peptizer and frequently at elevated temperatures.
Metalization 1) the deposition of a thin film pattern of conductive material onto a substrate to provide interconnection of electronic components or to provide conductive contacts. 2) the layer of high-conductivity metal used to interconnect devices on a chip. Aluminum is commonly used.
Microhardness hardness measured with an instrument having a smaller indentor and applying a lower force than the standard instrument, permitting measurements on smaller specimens or thinner sheets that are not amenable to measurement by normal instruments.
Micron(µm) a unit of length, one millionth of a meter.
Mill a machine used for rubber mastication, mixing or sheeting, having two counter-rotating rolls with adjustable longitudinal axis separation that usually rotate at different speeds.
Mismatch a defect resulting from differing cross-section dimensions in adjacent mold halves.
Mixer a machine that incorporates and disperses compounding ingredients into rubber to form a mix or a compound through the action of mechanical work (shear).
Mixer, internal a machine with a closed cavity in which a specially shaped rotor (or rotors) masticates the rubber or incorporates and disperses compounding materials into the rubber, or both.
Modulus, tensile See tensile stress, at given elongation the preferred term.
Modulus, Young’s the ratio of normal stress to corresponding strain for tensile or compressive stresses below the proportional limit of the material.
Mold cavity hollow space in the mold designed to impart the desired form to the product being made.
Mold marks surface imperfection transferred to a molded product from corresponding marks on a mold.
Mold release see release agent (mold).
Molding shrinkage the difference in dimensions between a molded product and the mold cavity in which it was molded, both the mold and product being at normal room temperature when measured.
Molding, compression the process of forming a material to a desired shape by flow induced by a force applied after a material is placed in the mold cavity.
Molding, injection the process of forming a material by forcing it from an external heated chamber through a sprue (runner, gate) into the cavity of a closed mold by means of a pressure gradient that is independent of the mold clamping force.
Molding, transfer the process of forming a material by forcing it from an auxiliary heated chamber through a sprue (runner, gate) into the cavity of a closed mold by means of a pressure gradient that is dependent on the mold clamping force.
Molecule smallest quantity of a substance that retains the properties of that substance.
Monomer a low-molecular-weight substance consisting of molecules capable of reacting with like or unlike molecules to form a polymer.
Mooney viscosity the measurement of the plasticity of compounded or uncompounded elastomeric seal material.
N’s
Necking the localized reduction in cross section that may occur in a material under tensile stress.
Negative resist photoresist that remains in areas that were not protected from exposure by the opaque regions of a mask while being removed by the developer in regions that were protected. A negative image of the mask remains following the development process.
Network a three-dimensional structure formed by interchain or intrachain bonding of polymer molecules in combination with chain entanglements.
Nip the radial clearance between rolls of a mill or calender on a line of centers.
Nitrile (Buna-N) a common hydrocarbon elastomer.
Non-fill defect resulting from the failure of the rubber to fill out all the mold pattern detail.
Non-polar pertaining to an element or compound which has no permanent dipole moment.
O’s
Occlusion process by which materials are entrapped within the folds of a given substance during manufacture.
Off-register misalignment of mold halves causing out-of round O-ringcross section.
Olefins a family of hydrocarbons with one carbon-carbon double bond.
Oligomer a polymer consisting of only a few monomer units, such as a dimer, trimer, tetramer, etc., or their mixtures.
O-ring see seal, 0-ring.
Outgassing the release of adsorbed or occluded gases or water vapor, usually by heating.
Oxidation a chemical reaction in which a compound loses electrons.
Oxidation the growth of oxide on silicon when exposed to oxygen. This process is highly temperature-dependent.
P’s
Paraffins saturated straight-chain hydrocarbons of the methane series.
Passivation the final layer in a semiconductor device, forming a hermetic seal over the circuit elements. Plasma nitride and silicon dioxide are materials primarily used for passivation.
Pellicle a thin film of an optical-grade polymer that is stretched on a frame and secured to a mask or reticle. This solves the problem of airborne contamination forming on the mask. The pellicle keeps the dirt out of the focal plane.
Perfluoroelastomer a fully fluorinated fluoroelastomer.
Permanent set the permanent distortion of an elastomer after being strained.
Permeability the permeation rate divided by the pressure gradient of the gas or vapor. For a homogeneous material that obeys Fick’s law, the permeability is equal to the product of the diffusion coefficient and the solubility coefficient of the gas or vapor.
Permeance the permeation rate divided by the pressure differential of a gas or vapor between opposite faces of a solid body.
Permeation rate the flow rate of a gas or vapor, under specified conditions, through a prescribed area of a solid body, divided by that area.
Physiosorption a physical adsorption process in which there are van der Waals forces of interaction between gas or liquid molecules and a solid surface.
Phosphosilicate glass(PSG) a material commonly used for dielectrics before metalization, also for passivation. These films are composed of phosphorous-doped silicon dioxide.
Photoresist the light-sensitive organic polymer film spun onto wafers and exposed using high-intensity light through a mask. The exposed photoresist is dissolved with developers, leaving a pattern of photoresist which allows etching to take place in some areas while preventing it in others.
Physical vapor deposition(PVD) the layering of a vapor, usually by means of evaporation or sputtering.
Pigment an insoluble compounding material used to impart color.
Plasma high-energy gas made up of ionized particles.
Plasma etching(PE) the use of energized gases to chemically remove a surface.
Plasma nitride a silicon-nitrogen film deposited using
PECVD, most often as a final passivation layer.
Plasma-enhanced chemical vapor deposition(PECVD) a deposition system primarily used for deposition of silicon oxide and silicon nitride films. A plasma is used in addition to a heat source which allows for lower temperature processing (200°””400°C).
Plasticizer a compounding material used to enhance the deformability of a polymeric compound.
Polar describing a molecule or radical that has, or is capable of developing, electrical charges. Polar molecules ionize in solution and impart conductivity.
Polymer a substance consisting of macromolecules characterized by the repetition (neglecting ends, branch junctions and other minor irregularities) of one or more types of monomeric units.
Polymer network a three-dimensional reticulate structure formed by chemical or physical linking of polymer chains.
Polysilicon (Poly) polycrystalline silicon, extensively used as conductor or gate material in a highly doped state.
Porosity the presence of numerous small cavities.
Post-cure heat or radiation treatment, or both, to which a cured or partially cured thermosetting plastic or rubber composition is subjected to enhance the level of one or more properties.
Pot life the period of time during which a reacting thermosetting plastic or rubber composition remains suitable for its intended use after mixing with a reaction-initiating agent.
Precision a concept of uniformity based on the magnitude of the random errors. The smaller the random errors, the higher the precision.
Primary accelerator the principal, highest concentration accelerator used in a vulcanizing system.
Processability the relative ease with which raw or compounded rubber can be handled in rubber machinery.
Processing aid a compounding material that improves the processability of a polymeric compound.
R’s
Radial clearance the difference in the radial dimensions between the sealing surfaces of a radial seal.
Radicals atoms or polyatomic molecules with at least one unpaired electron.
RCA Clean a multi-step wet chemical process to clean wafers before oxidation; named after RCA, the company that invented the procedure.
Reactive ion etching (RIE) an etching process that combines plasma and ion beam removal of the surface layer. The etchant gas enters the reaction chamber and is ionized. The individual molecules accelerate to the wafer surface. At the surface, the top layer removal is achieved by the physical and chemical removal of the material.
Recipe a formula, mixing procedure and any other instructions needed for the preparation of a product.
Recovery the degree to which a rubber product returns to its normal dimensions after being distorted.
Reinforcement the act of increasing the mechanical performance capability of a rubber by the incorporation of materials that do not participate significantly in the vulcanization process.
Release agent (mold) a substance applied to the inside surfaces of a mold or added to a material to be molded, to facilitate removal of the product from the mold.
Resilience the ratio of energy output to energy input in a rapid (or instantaneous) full recovery of a deformed specimen.
Resilience, impact the ratio of output to input mechanical energy in a rapid deformation and recovery cycle of a rubber specimen.
Resistivity, volume the ratio of the electric potential gradient to the current density when the gradient is parallel to the current in the material.
Retarder a material used to reduce the tendency of a rubber compound to vulcanize prematurely.
Reticle a reproduction of the pattern to be imaged on the wafer (or mask) by a step-and-repeat process. The actual size of the pattern on the reticle is usually several times the final size of the pattern on the wafer.
Reversion (vulcanization) deterioration of vulcanizate properties that may occur when vulcanization time is extended beyond the optimum.
Rubber a material that is capable of recovering from large deformations quickly and forcibly, and can be, or already is, modified to a state in which it is essentially insoluble (but can swell) in a boiling solvent such as benzene, methyl ethyl ketone or ethanol toluene azeotrope.
Rubber hardness degree, international(IRHD) a measure of hardness, the magnitude of which is derived from the depth of penetration of a specified indentor into a specimen under specified conditions. The scale is so chosen that zero would represent a material showing no measurable resistance to indentation, and 100 would represent a material showing no measurable indentation.
Runner the secondary feed channel for transferring material under pressure from the inner end of the sprue to the cavity gate.
S’s
Scanning electron microscope (SEM) microscope used to magnify images as much as 50,000 times by means of scanning with an electron beam. The impinging electrons cause electrons on the surface to be ejected. The ejected electrons are collected and translated into a picture of the surface.
Scarf joint a connection made with two ends cut at an angle and overlapping.
Scorch premature vulcanization of a rubber compound.
Scorch, Mooney the time to incipient cure of a compound when tested in the Mooney shearing disk viscometer under specific conditions.
Seal any material or device that prevents or controls the passage of matter across the separable members of a mechanical assembly.
Seal, 0-ring a product of precise dimensions molded in one piece to the configuration of a torus with circular cross section, suitable for use in a machined groove for static or dynamic service.
Secondary accelerator accelerator used in smaller concentrations, compared to the primary accelerator, to achieve a faster rate of vulcanization.
Semiconductor a material whose electrical resistivity is intermediate between that of conductors and insulators, in which conduction takes place by means of holes and electrons.
Set strain remaining after complete release of the force producing the deformation.
Shelf life see storage life, shelf.
Shock load the sudden application of an external force.
Shrinkage 1) decrease in volume of a seal in service due to extraction of fillers. 2) decrease in volume of an elastomeric compound during molding.
Silicide a compound of silicon with a refractory metal. Common silicide semiconductor films (used as interconnects) include titanium, tungsten, tantalum and molybdenum.
Silicon dioxide (SiO2) a non-conducting layer that can be thermally grown or deposited on silicon wafers. Thermal silicon dioxide is commonly grown using either oxygen or water vapor at temperatures above 900°C.
Silicon nitride (Si3N4) a nonconductive layer chemically deposited on wafers at temperatures between 600° and 900°C.
Silicone rubber poly dimethyl siloxane elastomer.
Solubility the ability or tendency of one substance to blend uniformly with another.
Sorption the term used to denote the combination of absorption and adsorption processes in the same substance.
Specific gravity the ratio of the weight of a given substance to the weight of an equal volume of water at a specified temperature.
Spew line line on the surface of a molded product at the junction of the mold parts.
Spin-on-glass (SOG) a dielectric suspended in a liquid solvent at room temperature, allowing the material to be spun onto a wafer. Most SOG films are siloxane polymers dissolved in alcohol-ketone solvents. After being spun on the wafer, the wafers must be baked to drive off the solvent.
Sputtering a method of depositing a thin film of material on wafer surfaces. A target of the desired material is bombarded with radio frequency-excited ions which knock atoms from the target; the dislodged target material deposits on the wafer surface.
Squeeze the compression of a seal, usually expressed as a percentage calculated by dividing the deformation by the original seal cross-sectional diameter.
Standard clean one a mixture of ammonium hydroxide, hydrogen peroxide and UPDI. The first step in the RCA Cleaning process, which is designed to remove organic material.
Standard clean two a mixture of hydrochloric acid, hydrogen peroxide and UPDI. The second step in the RCA Cleaning process, which is designed to remove metals and other inorganic material.
Static seal a seal in which the sealing surfaces do not move relative to each other.
Steam oxide thermal silicon dioxide grown by bubbling a gas (usually oxygen or nitrogen) through water at 100°C.
Stepper a machine which steps a reticle directly onto the wafer. A reticle can be produced at lower defect level and with tighter dimensional control than an entire mask, resulting in wafer images having fewer defects. Alignment of reticle to wafer is accomplished by reflecting a laser beam through a special reticle pattern (alignment target) and off a corresponding pattern on the wafer.
Stiction the increase in static friction resulting from prolonged seal compression.
Stiffness, bending the force required to produce a bent configuration under specified conditions.
Stock see compound.
Storage life, shelf the period of time after production during which a material or product that is stored under specified conditions retains its intended performance capabilities.
Strain the unit change, due to force, in the size or shape of a body referred to its original size or shape.
Stress the intensity, at a point in a body, of the internal forces (or components of force) that act on a given plane through the point.
Stress relaxation the decrease in stress after a given time at constant strain.
Stripping removal process; usually refers to photoresist.
Susceptor a component of many equipment systems on which the wafer is placed. Frequently made of high-purity graphite.
Swelling the increase in volume of a specimen immersed in a liquid or exposed to a vapor.
T’s
Target the material to be sputtered during the sputtering process.
Tear mechanical rupture initiated and propagated at a site of high stress concentration caused by a cut, defect or localized deformation.
Tear strength the maximum force required to tear a specified specimen, the force acting substantially parallel to the major axis of the test specimen.
Tensile set the extension remaining after a specimen has been stretched and allowed to retract in a specified manner expressed as a percentage of the original length.
Tensile strength the maximum tensile stress applied during stretching a specimen to rupture.
Tensile stress a stress applied to stretch a test piece (specimen).
Tension fatigue fracture, through crack growth, of a component or test specimen subjected to a repeated tensile deformation.
Tension set the strain remaining after a test piece or product has been stretched and allowed to retract.
Terpolymer a polymer formed from three monomer species.
Thermal carbon black type of carbon black produced under controlled conditions by the thermal decomposition of hydrocarbon gases in the absence of air or flames.
Thermal degradation irreversible and undesirable change in the properties of a material due to exposure to heat.
Thermal diffusion a process by which dopant atoms diffuse into the wafer surface by heating the wafer in the range of 1,000°C and exposing it to vapors containing the desired dopant.
Thermoplastic elastomer(TPE) a diverse family of rubberlike materials that, unlike conventional vulcanized rubbers, can be processed and recycled like thermoplastic materials.
Topography the characteristic of a surface referring to its degree of flatness and smoothness.
Torr pressure unit; international standard unit replacing the English measure, millimeters of mercury (mm-Hg).
TR-10 a test method for approximating the low-temperature capabilities of an elastomer.
Transistor a semiconductor device that uses a stream of charge carriers to produce active electronic effects. The name originated from the electrical characteristic of transfer resistance.
Transition, first order a reversible change in phase of a material; in the case of polymers, usually crystallization or melting.
Transition, glass (Tg ) the reversible physical change in a material from a viscous or rubbery state to a brittle, glassy state.
U’s
Ultrapure deionized water (UPDI) a highly purified water in which all charged species of ionizable organic and inorganic salts have been removed.
Ultraviolet (UV) electromagnetic radiation in the wavelength 4”” 400 nanometers.
UV stabilizer a compounding material that, through its ability to absorb ultraviolet radiation and render it harmless, retards the deterioration caused by sunlight and other UV light sources.
V’s
Vacuum evaporation a deposition technique whereby the deposited gas results from an evaporation process.
Van der Waals force an attractive force between two atoms due to a fluctuating dipole moment in one molecule inducing a dipole moment in the other molecule which then interact.
Vapor pressure the pressure of the vapor in equilibrium with its liquid or solid phase.
Virtual leak an apparent leak in a vacuum system that is often traceable to some internal release of occluded and/or sorbed gases.
Viscoelasticity a combination of viscous and elastic properties in a material with the relative contribution of each being dependent on time, temperature, stress and strain rate. Viscosity the resistance of a material to flow under stress.
Viscosity, Mooney a measure of the viscosity of a rubber or rubber compound determined in a Mooney shearing disk viscometer.
Void, cellular material a cavity unintentionally formed in a cellular material and substantially larger than the characteristic individual cells.
Volatilization also known as vaporization, the conversion of a chemical substance from a liquid or solid state to a gaseous or vapor state.
Volt a unit of electromotive force or difference in electric potential.
Volume swell the increase in dimension caused by the absorption of a fluid.
Vulcanizate the product of vulcanization, a cross-linked rubber.
Vulcanization an irreversible process during which a rubber compound, through a change in its chemical structure (for example, cross-linking), becomes less plastic and more resistant to swelling by organic liquids, while elastic properties are conferred, improved, or extended over a greater range of temperature.
Vulcanizing agent compounding material that produces cross-linking in rubber.
Vulcanizing system the combination of a vulcanizing agent and, as required, accelerators, activators and retarders used to produce the desired vulcanization characteristics or vulcanizate characteristics.
W’s
Wafer flat flat area(s) ground onto the wafer’s edges to indicate the crystal orientation of the wafer structure and the dopant type.
Warm-up the reduction in viscosity of a rubber or rubber mix, by mechanical work and heat, to render it suitable for further processing.
Wavelength the length of the wave to complete one cycle.
Wicking transmission of a gas or liquid, due to a pressure differential or capillary action, along fibers incorporated in a rubber product.
Wiper ring a device designed to keep out foreign material.
Y’s
Yield point that point on the stress-strain curve, short of ultimate failure, where the rate of stress with respect to strain goes through a zero value and may become negative.
Yield strain the level of strain at the yield point.
Yield stress the level of stress at the yield point.
Glossary are courtesy of ASTM D1566