SEMATECH Dictionary of Semiconductor Terms

A-Am | An-Az | B | C-Ch | Ci-Com | Con-Cz | D-De | Df-Dz | E-En | Eo-Ez | F-Fl
Fm-Fz | G | H | I | J-K | L | M-Mes | Met-Mz | N | O | P-Ph | Pi-Pq | Pr-Pz | Q | R
S-Se | Sh-So | Sp-Sta | Ste-Sz | T-Th | Ti-Tz | U-V | W-Z

"An - Az "

analog adj		A signal in an electronic circuit that takes on a continuous range of values rather than only a few discrete values; a circuit or system that processes analog signals. [1994 National Technology Roadmap for Semiconductors] Contrast discrete.
analytical model n		a representation of a process or phenomenon by a set of solvable equations. Contrast simulation. [SEMATECH]
ancillary areas		subordinate or support areas outside the cleanroom. [SEMATECH]
angle-resolved scattering (ARS) n		technique that measures light scattered from particlesas a function of angle; used to characterize particles. [SEMATECH]
angstrom (Å) n		unit of linear measure equal to one ten billionths of a meter (10-10 m). (The diameter of a human hair is approximately 750,000 Å.) The preferred SI unit is nanometers. 10 Å=1 nm. [SEMATECH]
anion n		an ion that is negatively charged. [SEMATECH]
anion-exchange resin n		an ion-exchange resin capable of the reversible exchange of negatively charged ions. [SEMATECH]
anisotropic adj		exhibiting different physical properties in different directions. NOTE-In semiconductor technology, the different directions are defined by the crystallographic planes. [SEMI M1-94 and ASTM F1241] Also called nonisotropic and aeolotropic. Also see anisotropic etch.
anisotropic etch n		a selective etch that exhibits an accelerated etch rate along specific crystallographic planes. NOTE-Anisotropic etches are used to determine crystal orientation, to expose crystal defects, and to facilitate dielectric component isolation. [SEMI M1-94 and ASTM F1241] Also called preferential etch.
anneal n		a high-temperature operation that relieves stress in silicon, activates ion-implanted dopants, reduces structural defects and stress, and reduces interface charge at the silicon-silicon dioxide interface. [SEMATECH]
anodic coating n		a protective, decorative, or functional coating formed by conversion of the surface of a metal in an electrolytic oxidation process. [ASTM B374-93]
anomaly		see defect.
anoxia n		an abnormal condition characterized by a relative or total lack of oxygen; may be local or systemic. [SEMATECH]
ANSI		see American National Standards Institute.
antireflective coating (ARC) n		a layer of dielectric material deposited on a wafer before resist to minimize reflections during resist exposure. [SEMATECH]
antimony (Sb) n		a brittle, tin-white, metallic chemical element of crystalline structure. Antimony is used as an n-type dopant in silicon, often for the buried layer. [SEMATECH]
apex chip n		on a semiconductor wafer or other substrate, any material missing from the edge of a wafer and having at least two distinct interior boundaries that form one or more distinct intersections. [SEMI M10-89] Also see chip.
API		see application programming interface.
apnea n		an absence of spontaneous respiration. [SEMATECH]
application-level synthesis n		synthesis from specifications described in a style natural to an application area, such as dataflow diagrams for digital signal processing applications. [1994 National Technology Roadmap for Semiconductors]
application programming interface (API) n		a means of invoking services in the code of an application. An API is needed for each interface of any architecture. [SEMATECH]
application software n		the software performing the specific task of the equipment or the host computer. [SEMI E4-91]
AQL		see acceptable quality level.
aqueous extraction n		a procedure for obtaining an extract (usually an ionic water solution) of thermosetting molding plastics or other plastic materials used in microelectronic device manufacture. The extract is analyzed by standard methods to determine the pH, conductivity, and ionic composition. [SEMI G12-82]
ARC		see antireflective coating.
architecture n		of a computer system, a defined structure based on a set of design principles. The definition of the structure includes its components, their functions, and their relationships and interactions. [SEMATECH]
area contamination n		foreign matter on localized portions of a wafer or substrate surface. [SEMI M3-88]
area defect		: see extended light scatterer.
argon (Ar) n		a "rare gas," although more abundant than any of the other rare gases. Argon is monatomic (its molecules having only one atom) and characterized by its extreme chemical inactivity. It is colorless, odorless, tasteless, and somewhat soluble in water. Argon is used as an inert gas in purging, blanketing, and pressurizing systems. It also is used in chemical vapor deposition, sputtering, plasma and reactive ion etching, and annealing. Argon normally is stored as a cryogenic liquid. [SEMI C3.1-88]
array n		1 : in lithography, an arrangement of repetitive patterns on a die, such as an array of memory cells. [SEMATECH] 2 : in lithography, all of a class of functional patterns taken as a group that appears on a wafer or that is produced by stepping (as on a photographic material). [ASTM F127-84] 3 : in packaging, a group of pads, pins, or circuits arranged in rows and columns on one substrate. [SEMATECH]
ARS		see angle-resolved scattering.
arsenic (As) n		a highly poisonous chemical element, which is brittle and steel gray in color. Arsenic is often used as an n-type dopant for buried layer predisposition. [SEMATECH] Also see n-type.
arsenic trioxide (As2O3) n		a white powder used as a solid source of arsenic for forming n-type regions in semiconductors. [SEMATECH] Also called white arsenic.
arsine (AsH₃) n		a highly toxic, flammable, and colorless gas with a disagreeable garlic-like odor. It is a hemolytic poison. Arsine is used in the semiconductor industry for n-type doping of epitaxial films, for diffusion processes, in ion implantation, for the production of gallium arsenide phosphide films, and as a source for arsenic silicate glass films. [SEMI C3.2-88]
artifact n		1 : a physical standard against which a parameter is measured; for example, a test wafer used for testing parametric drift in a machine. [SEMATECH] Also called standard reference material. 2 : a superficial or unessential attribute of a process or characteristic under examination; for example, a piece of lint on a lens that appears through a microscope to be a defect on a die. [SEMATECH] 3 : in surface characterization, any contribution to an image from other than true surface morphology. Examples include contamination, vibration, electronic noise, and instrument imperfections. [SEMATECH]
aseptic methods n		methods that minimize contamination of a sample by extraneous microorganisms. [SEMATECH]
ash v		to apply heat to a material until the material has been reduced to a mineral residue. [SEMATECH]
asher n		a machine used to remove resist from substrates. [SEMATECH]
ashing n		the operation of removing resist from a substrate by oxidation; a reaction of resist with oxygen to remove the resist from the substrate. [SEMATECH]
aspect ratio n		1 : in etch, the depth-to-width ratio of an opening on a wafer. [SEMATECH] 2 : in feature profile, the ratio of height to width of a feature. [SEMATECH]
asphyxia n		severe deficiency of oxygen or greater-than-normal amounts of carbon dioxide in the blood, leading to loss of consciousness and, if not corrected, death. Common causes include inhalation of toxic gas or smoke, aspiration of vomitus, foreign bodies in the respiratory tract, and poisons. [SEMATECH]
assay n		the determination of the content of a specific component with no evaluation of other components. [SEMI C3-94]
assignable cause		see special cause.
assist n		any unplanned interruption or variance from specifications of equipment operation that requires human intervention of less than six minutes to correct. After six minutes, an assist becomes a failure. [SEMI E10-92]
ASO		see automatic shutoff.
asynchronous adj		independent of time-controlled sequence or chronological occurrence. [SEMATECH]
ataxia n		an abnormal condition characterized by impaired ability to coordinate movement. [SEMATECH]
atmosphere (atm) n		a unit of pressure equal to the pressure exerted by a vertical column of mercury 760 mm high, at a temperature of 0 degrees C, and under standard gravity. One technical atmosphere equals 1 kg X f/cm2 (14.7 pounds per square inch). [ASTM D1356 REV A-73]
atomic absorption spectrometry n		the measurement of the light absorbed at the wavelength of resonance lines by the unexcited atoms of an element. [ASTM C859-92]
atomic force microscopy (AFM) n		a microscopy technique based on profilometry using an atomically sharp probe that provides three-dimensional highly magnified images. During AFM, the probe scans across a sample surface. The changes in force between the sample and the probe tip cause a deflection of the probe tip that is monitored and used to form the magnified image. [SEMATECH]
atomic percent n		in electron spectroscopy for chemical analysis (ESCA) of plastic surface composition, the number of atoms of a particular element present in every hundred atoms within the ESCA detection volume. [SEMATECH]
atomic transfer n		in automated material movement, the transfer of a single transfer object from Equipment A directly to Equipment B with only one change in ownership. An atomic transfer is the basic unit of movement in automated material movement. [Adapted from SEMI E32-94]
ATPG		see automatic test pattern generation.
at-speed test n		any test performed on an integrated circuit that tests the device at its normal operating clock frequency. [1994 National Technology Roadmap for Semiconductors]
attribute n		1 : the real-world characteristics or properties of an entity, recorded as part of an entity type. 2 : properties of an entity; an entity is said to be described by its attributes. In a database, the attributes of an entity have their analogues in the fields of a record. In an object database, instance variables may be considered attributes of objects. 3 : element of information pertaining to an object. 4 : value associated with a type definition. [SEMATECH] Also see object attribute.
attributes n, pl		qualitative data that can be counted. Examples include the number of particles per wafer, number of failed die per wafer, and particle density per wafer. Attributes are measured on a discrete scale. [SEMATECH]
Auger electron spectroscopy (AES) n		the energy analysis of Auger electrons produced when an excited atom relaxes by a radiationless process after ionization by a high-energy electron, ion, or X-ray beam. [SEMATECH]
Auger process n		the radiationless relaxation of an atom involving a vacancy in an inner electron shell. An electron is emitted, which is referred to as an Auger electron. [ASTM E673-90]
autodoping n		in the manufacture of silicon epitaxial wafers, the incorporation of dopant originating from the substrate into the epitaxial layer. [SEMI M11-94 and ASTM F1241] Also called self-doping. Also see doping.
automated material handling system (AMHS) n		equipment that helps control the flow of material in a manufacturing facility; e.g., robots, computers, sensors, and protective carriers. [SEMATECH]
automated system test n		automatic insertion of testability features at the system level, driven by a high-level description of the system and identification of appropriate test methods for each system block. [1994 National Technology Roadmap for Semiconductors]
automatic shutoff (ASO) n		in gas source control equipment, a remotely actuated valve, preferably the cylinder valve, but possibly a valve located close to the cylinder valve, that can isolate the product as close to the cylinder valve as possible. It may also be a device that attaches to the cylinder valve stem or handle to close the valve. [SEMI F13-93]
automatic test pattern generation (ATPG) n		the automatic development of vectors which, when applied to an integrated circuit, permit faults to be detected in the performance of the integrated circuit. [1994 National Technology Roadmap for Semiconductors]
automatic valve n		a valve with an actuation device that can be operated remotely, such as a pneumatically or electrically controlled valve. [SEMATECH]
availability n		1 : of equipment, the number of hours producing, plus standby time, divided by total available hours; expressed as a percentage: 168 hours - (facilities downtime + equipment downtime + engineering time + setup and test time)/168 hours X 100. [SEMATECH] 2 : of equipment, the probability that the equipment will be in a condition to perform its intended function when required. [SEMI E10-92] 3 : of computer systems, the amount of time a computer system, communications network, or database system is ready to support normal activity. [SEMATECH]
available equipment capacity n		potential number of product wafers the equipment could process during the equipment uptime period if there were no engineering or standby time allowed. [SEMATECH]
average defect count n		in optical analysis of surface condition, the result of dividing the total number of defects on a single photomicrography by the number of squares in the grid used. [SEMATECH]
azeotrope n		a liquid mixture with a constant maximum or minimum boiling point lower or higher than the boiling points of its components and with the capacity to distill without change in composition. [SEMATECH] Also see eutectic.
azimuth n		in ellipsometry, the angle between the major axis of the ellipse and the plane of incidence. [SEMI M1-94 and ASTM F1241] Also see ellipsometer.

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