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

"Eo - Ez"

EOT n		"Ready to Receive" handshake code. NOTE-EOT (derived from End Of Transfer) is one of the four standard handshake codes used in block transfer protocol. The code EOT (00000100) corresponds to the ASCII code that has the same pattern. [SEMI E4-91]
EP		see electropolish.
epifluorescence n		in analyzing specimens for surface associated biofilms, the illumination of the specimen from above the specimen plane by excitation illumination, the absorption of the light by bound dyes, and the observation of the light re-emitted by those dyes. [SEMATECH]
epi profile slope n		in the manufacture of silicon epitaxial wafers, the difference between the net carrier density at 0.75 of the layer thickness and the net carrier density at 0.25 of the layer thickness, divided by one-half the layer thickness. [SEMI M2-94]
epitaxial layer n		in semiconductor technology, a layer of a single crystal semiconducting material grown on a host substrate which determines its orientation. [SEMI M2-94 and ASTM F1241]
epitaxy (epi) n		a silicon crystal layer grown on top of a silicon wafer that exhibits the same crystal structure orientation as the substrate wafer with a dissimilar doping type or concentration or both. Examples are p/p+, n/n+, n/p, and n/n. [SEMATECH] Also see epitaxial layer.
equilibrium capacitance n		that capacitance reached after a metal oxide semiconductor (MOS) specimen at a fixed bias is illuminated and then allowed to stabilize in darkness. [ASTM F1241]
equilibrium vapor concentration (EVC) n		the state of a regulated material at which vapor pressure has stabilized and is no longer rising or falling. The EVC value in ppm of a regulated material is determined by multiplying the vapor pressure by 106 and dividing by atmospheric pressure (760 mm Hg at sea level). [SEMI F6-92]
equipment n		1 : a specific piece of machinery, apparatus, process module, or device used to execute an operation. [SEMATECH] 2 : the intelligent system that communicates with a host computer. [SEMI E4-91]
equipment availability n		1 : 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. 2 : the probability that the equipment will be in a condition to perform its intended function when required. [SEMI E10-92]
equipment cycle n		one complete operational sequence of processing, manufacturing, and testing steps. In single-unit processing systems, the number of cycles equals the number of units processed. In batch systems, the number of cycles equals the number of batches processed. [SEMI E10-92]
equipment dependent uptime n		the percentage of time that the equipment is in a condition to perform its intended function during the period of operations time minus the sum of all maintenance delay, out-of-spec input downtime, and facilities-related downtime. This calculation is intended to reflect equipment reliability and maintainability based solely on equipment merit. [SEMI E10-92] Also see equipment uptime.
equipment downtime n		the hours when the equipment is not in a condition or is not available to perform its intended function; does not include any portion of nonscheduled time. [SEMI E10-92]
equipment failure n		any interruption or variance from the specifications of equipment operation that requires the replacement of a component (other than specified consumables) because of degradation or failure. Also includes assists that interrupt operation and require more than six minutes. [SEMI E10-92]
equipment life cycle		see life cycle.
equipment maintainability n		the probability that the equipment will be retained in, or restored to, a condition in which it can perform its intended function within a specified period. [SEMI E10-92]
equipment model n		in communications and control of semiconductor manufacturing equipment, a definition based on capabilities, scenarios, and SECS-II messages that manufacturing equipment should perform to support an automated manufacturing environment. [SEMI E30-94] Also see Generic Equipment Model and specific equipment model.
equipment reliability n		the probability that equipment will perform its intended function, within stated conditions, for a specified period. Reliability is considered only for the time during which the equipment is operated (cycled). The two different variables applied to the measurement of equipment reliability are productive time and equipment cycles. [SEMI E10-92] Also see mean (productive) time between failures, mean cycles between failures, mean (productive) time between assists, and mean cycles between assists.
equipment set n		a group of individual pieces of related equipment in close proximity that performs a commonly used process sequence. [SEMATECH]
equipment states n		equipment conditions and time periods associated with equipment performance. The six equipment states are defined by function, not by organization (the people who perform the tasks). They are the productive state, the standby state, the engineering state, the scheduled downtime state, the unscheduled downtime state, and the nonscheduled state. [SEMI E10-92]
equipment uptime n		the amount of time when the equipment is in a condition to perform its intended function, including productive, standby, and engineering time; does not include any portion of nonscheduled time. [SEMI E10-92]
equipment utilization n		the percentage of time the equipment is performing its intended function during a specified time period. [SEMATECH] t
equivalent release concentration (ERC) n		in gas enclosure testing, the theoretical concentration of a process gas that would be measured outside an enclosure in the event of a process line failure. The ERC can be expressed as a percentage of the threshold limit value (TLV) or permissible exposure limit (PEL) of the process gas. [SEMI F15-93]
ergonomics n		the science that deals with adapting the work environment to the needs of the worker. [SEMATECH]
error n		a discrepancy between a computed, observed, or measured value or condition and the true, specified, or theoretically correct value or condition. [SEMATECH]
ESC		see electrostatic chuck.
ESD		see electrostatic discharge.
estimator n		a program or operator which, when applied to a system or circuit representation, can obtain an estimate of some parameter or value, for example, power, speed, or manufacturing yield. [1994 National Technology Roadmap for Semiconductors]
etch 1 n		a category of lithographic processes that remove material from selected areas of a die. Examples are nitride etch and oxide etch. [SEMATECH] 2 : in the manufacture of silicon wafers, a solution, a mixture of solutions, or a mixture of gases that attacks the surfaces of a film or substrate, removing material either selectively or nonselectively. [SEMI M1-94 and ASTM F1241] Also see anisotropic etch, preferential etch, dry plasma etch, reactive ion etch, and wet chemical etch.
etchant n		an acid or base (in either liquid or gaseous state) used to remove unprotected areas of a wafer layer. Examples are potassium hydroxide, buffered oxide etch, and sulfur hexafluoride. [SEMATECH]
etched leadframe		leadframes produced by masking and etching the exposed metal in an acidic bath. [SEMATECH] Also see compensation, etch factor, undercut, and mismatch.
etched metal mask		see mask, etched metal.
etched polysilicon n		polysilicon that has been cleaned with acid to remove surface contamination. [SEMI M16-89] Also see polycrystalline silicon.
etch factor n		in the etching of dual inline package (DIP) leadframes, the ratio of etched depth to lateral etching during the production of etched metal leadframes. [SEMI G19-84] Also see compensation and undercut.
etch pilots n		test wafers for etch. [SEMATECH]
etch pit n		a pit, resulting from preferential etching, localized on the surface of a wafer at a crystal defect or stressed region. [ASTM F1241]
eth		see sensitivity, threshold energy.
eutectic n		alloy or solution with components distributed in the proportions necessary to minimize the melting point. [SEMATECH] Also see azeotrope.
evaluative line pattern n		in the measurement of photolithographic instruments, a pattern in the image constructed of three to five straight parallel lines, such that the lines are oriented at some specified angle with respect to the standard coordinates, their width is equal to the practical resolution, and their pitch is twice the practical resolution. [Adapted from SEMI P25-94]
evaporation n		an operation that uses heat and vacuum to remove a material from a source and deposit it on a surface. The deposition step of an evaporation operation is condensation. [SEMATECH]
evaporator n		a high-vacuum apparatus for evaporating materials. [SEMATECH]
EVC		see equilibrium vapor concentration.
event n		1 : in equipment communications, a detectable occurrence significant to the equipment. [SEMI E30-94] 2 : in equipment communications, the occurrence of a change in the condition of a system, such as lot complete or temperature over range. [SEMI 2309, proposed] Also see alarm.
exception agent n		the entity that manages access to and reporting of information on abnormal situations in equipment. It achieves this by defining exception conditions, each related to a significant abnormal situation. It may provide services for a decision authority to direct the recovery from certain situations. [SEMI E41-95]
exception condition n		a condition managed by an exception agent for reporting of and recovery from an abnormal situation in the equipment. [SEMI E41-95]
excessive leakage n		in the seal testing of fluorocarbon tube fittings, gas leakage from a fitting connection that produces more bubbles than can be humanly counted. [Adapted from SEMI F12-93]
excess flow control n		a fail-safe system designed to shut off flow caused by a rupture in the pressurized piping systems. [SEMI S2-93]
excess flow valve (EFV) n		a valve inserted in a supply line designed to shut off the flow positively in the event its predetermined flow is exceeded. [SEMI S2-93]
excimer laser n		a laser containing a noble gas, such as helium or neon, that is based on a transition between an excited state and a rapidly dissociating ground state. [SEMATECH]
exclusion zone n		a restricted area within a process or cassette module reserved for access by the transport module end effector during wafer handling. [SEMI E22-91]
expansion characteristics n		of molding compounds, see coefficient of thermal expansion and glass transition temperature.
expansion slot n		a slot cut into the metal bars between individual frames of a leadframe strip in order to prevent pitch variations between the frames due to molding compound shrinkage. Pitch variations from frame to frame along the strip cause alignment problems for subsequent lead trim tooling. [SEMATECH]
expected block n		a message block expected by the message protocol. NOTE-In order to determine if a block is one of those expected, the block header information is compared with the header information in a list of expected blocks. [SEMI E4-91]
expert system n		a software system capable of solving problems using heuristic techniques. [SEMATECH]
exposure n		1 : the process of subjecting a photosensitive material to light or other radiant energy. [SEMATECH] 2 : the amount of light or other radiant energy received per unit area of sensitized material. [ASTM F127-84]
exposure field n		the area of a wafer covered by a single exposure. [SEMI P18-92]
extended light scatterer (XLS) n		a feature larger than the spatial resolution of the inspection equipment, on or in a wafer surface, resulting in increased light scattering intensity relative to that of the surrounding wafer surface. [ASTM F1241] Also called area defect.
external lead n		the sections of a leadframe that connect the finished device to external circuitry such as a printed circuit board. [SEMATECH] Contrast internal lead.
extractables n		contaminants, removable by solvent action using a special solvent and procedure. Typically, extractables are nonparticulate (as in a polymer tube) or nonfibrous (as in textiles). Examples are plasticizers, oils, and resins. [SEMATECH]
extraction n		the generation of a set of values for desired parameters based on the analysis of a design representation. For example, the generation of a transistor net list or a set of parasitic capacitances and resistances from the detailed layout representation of an integrated circuit. [1994 National Technology Roadmap for Semiconductors]
extremely low frequency (ELF) n		:extremely low frequency magnetic fields, of about 1 Hz to 1 kHz, generated by current flow, most commonly 60 Hz in the U.S. and 50 Hz in Europe, within equipment and facilities. [SEMI E33-94] Also see ELF-sensitive equipment.
extrinsic semiconductor n		a semiconductor in which the free carriers are predominantly of one type. Extrinsic semiconductors in which electrons are the dominant (majority) carrier are n-type, and extrinsic semiconductors in which holes are the dominant (majority) carrier are p-type. [SEMATECH] Contrast intrinsic semiconductor. Also see conductivity type.
eyepiece n		in an optical instrument, the lens system used for magnification of the image formed by the objective. [ASTM E175-82]

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