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Abrasive
a granular compound used for grinding or cutting.
Abrasive characteristics
The mold roughening or wearing characteristics of a plastic molding compound used to encapsulate electronic devices. These characteristics are the result of the fillers, such as silica, that are added to the plastic in order to control the molding and molded characteristics of the material. Also see molding compound.
Absolute pressure
The pressure measured relative to zero pressure(perfect vacuum).
Absorb
The taking up of a liquid or gas into the bulk of another material.
Abstract class
A class with no instances that is created only for the purpose of organizing a class hierarchy or defining methods and variables that will apply to lower-level classes. The term "virtual class" refers to the same concept.
Abstract data type
A data type that is defined by a programmer and not built into the programming language. Abstract data types are typically used to create high-level structures that correspond to the real-world objects represented in a program.
Accelerometer
Time interval between the instant that a piece of information is sent to the memory device and the instant it returns.
Acceptable quality level(AQL)
Generally, 95% confidence that material of the stated AQL will pass sample inspection. This is distinct from reliability, which measures failures over an extended period of time.
Acceptance criteria
The criteria that a system or component must satisfy to be accepted by a user or customer.
Accept number
The maximum number of devices that may fail a sample test without causing rejection of the lot.
Acceptor
In a semiconductor, an impurity in a semiconductor that accepts electrons excited from the valence band, leading to hole conduction.
Access
An engineering data analysis system that compiles a database of wafer fabrication facility (fab) system, control, production, and structural data for yield analysis, manufacturing analysis, and production indices. Abbreviation for analysis computer for component engineering service support.
Access time
A time interval that is characteristic of a storage device and is essentially a measure of the time required to communicate with that device.
Accumulation condition
the region of the capacitance-voltage (C-V) curve for which a 5-V increment toward a more negative voltage for p-type material, or toward a more positive voltage for n-type material, results in a change of less than 1% in the maximum capacitance, Cmax (The "max" part of the abbreviation "Cmax"is written with subscript lowercase letters.)
Accuracy
In statistical process control, the compliance of the measured or observed value to the true value or accepted reference value
Acetic acid(CH3COOH)
A sour, colorless, liquid compound that is a component of vinegar.
Acidosis
An abnormal increase in hydrogen-ion concentration in the body caused by and accumulation of an acid or loss of a base ; may be respiratory, metabolic, or renal in nature.
Acid tank
Achemically inactive receptacle containing acid for etching, cleaning, or stripping wafers.
ACK
In message transfer, "Correct Reception" handshake code. NOTE-The name (derived from ACKnowledged) of one of the four standard handshake codes used in block transfer protocol. The code ACK (00000110) corresponds to the ASCII code that has the same pattern.
Across-the seat test
A test for leakage across the internal seal of a test component (for example, from one side of the valve seat to the other).
Active area
The region of thin oxide on a die or wafer in which transistors and other circuits reside.
Active device
A device which, when subjected to a current or voltage, exhibits either gain (amplification) and/or control characteristics, or a device which converts input signal energy into output signal energy through interaction with the energy from an auxiliary source(s)
Active equipment
Equipment that loads a cassette on the cassette stage of another piece of equipment, or unloads a cassette from the cassette stage of another piece of equipment.
Active transfer partner
In automated material movement, a transfer partner that physically participates in the micro-level portion of a transfer, either by moving the transfer object or by moving impediments within the transfer envelope, such as doors or clamps. NOTE-This term refers to the micro-level transfer phase only, and not to any setup activities prior to the transfer. For example, a port door may be opened during setup phase by passive partner.
Actual equipment production
Actual number of product wafers processed during productive time (including equipment loading and unloading)
Action flow
In mass flow devices, the gas flow as measured by an external standard, not the electrical output of a mass flow meter.
Actuation cycle
The full operation of a valve, such as from a fully opened position to fully closed and back to fully opened.
Acute health effect
A severe, usually critical, and often dangerous adverse effect on a human or animal body, with severe symptoms that rapidly change and exposure of short duration.
Acute toxicity
The acute adverse effects resulting from brief exposure to a material.
A/D Converter
(Analog/Digital converter) A device that converts continuously varying analog signals from instruments that monitor such conditions as movement, temperature, sound, etc., into binary code for the computer. It may be contained on a single chip or can be one circuit within a chip.
Adhesion, resist edge
The ability of the edge of an image in a developed resist coating to adhere to its substrate under applied physical or chemical stress.
Adhesive stringer
On a photolithographic pellicle, any detectable protrusion from the edge of the adhesive.
Adjacent character misalignment
In the serial alphanumeric marking of silicon wafers, the vertical distance (R) between the character baselines of two adjacent characters on the same line.
Adjusted decibel
A unit used to express the relationship between the interfering effect of a noise frequency and a noise power level.
Aggregation object
In equipment communications, an object that is composed (made up) of other objects. An aggregation may lose some degree of integrity if one of its components is missing.
Air flow interruptionDisruption of airflow that causes particles to travel in a manner that may potentially contaminate the product or process fluids.
Air velocity (VA)
In the thermal testing of semiconductor devices, the velocity of the cooling air at a specified location upstream from the device under test. Air velocity is measured in liner feet per minute.
Alarm
Implementation-dependent interpretation of an event ; supplier-and situation-specific events.
Algorithm
A set of precisely defined rules, processes, or operations for solving a problem in a finite number of steps.
Algorithmic
Pertaining to problem-solving methods that use a precisely defined, finite set of rules, operations, or procedures.
Align expose
An operation in a lithography process during which a resist-coated substrate is put into proper relative position or orientation to an exposed to light.
Alignment
1 : the accuracy of the relative position of an image on a reticle with reference to an existing image on a substrate
2 : a procedure in which a wafer is correctly positioned relative to a reticle.
3 : the mechanical positioning of reference points on a wafer or flat panel display substrate (also called alignment marks or alignment targets) to the corresponding points on the reticle or reticles. The measure of alignment is the overlay at the positions on the wafer or substrate where the alignment marks are placed.
Alignment key
see alignment mark.
Alignment pocket
Any form of mechanical shape (other than flat) local to a cassette or container designed to position or otherwise externally constrain a container to a production tool.
Alignment target
See alignment mark.
Alkali
Any compound that has highly basic properties. Alkalis are often hydroxides of alkali metals (metals that belong to group IA of the periodic tale, including Li, Na, K, Rb, Cs and Fr).
An abnormal increase in hydrogen-ion concentration in the body caused by and accumulation of an acid or loss of a base ; may be respiratory, metabolic, or renal in nature
Alloy
1 : a composite of two or more elements, of which at least one is metal.
2 : a thermal cycle in which two or more discrete layers (of which at least one is metal) react to allow good electrical contacts.
Alluvial
Describes soil that contains sediment deposited by water flow.
Alpha particles
Helium nuclei emitted as a result of the radioactive decay of trace amounts of naturally occurring uranium and thorium found in semiconductor packaging materials. Alpha particles, if not properly controlled can cease soft errors in dynamic memories.
Alpha test
Performance testing, done at a manufacturer's site, on a preproduction version of a process tool. Testing is performed by applications engineering under development engineering's supervision. No design changes are made during the testing period.
Alphanumeric marking
A system of marking wafers using machine-readable letters, numbers, a dash, or a period.
Aluminized width
In a semiconductor package, the width of the area coated with a protective layer of aluminum. This area covers most of the top formed width.
Aluminum (Al)
A metal used to interconnect the devices on a wafer and to interconnect external devices or components.
Aluminum chloride (AlCl3)
A crystalline solid formed in the chambers of aluminum plasma etchers and concentrated in the cold traps.
Aluminum oxide (Al2O3)
An abrasive used in grinding operations. Also, the native oxide growth that occurs on freshly deposited aluminum. Sapphire is the monocrystalline form of aluminum oxide
Ambient
Room temperature.
Ambient pressure
In mass flow controllers, the absolute pressure of the medium surrounding the device
Ambient temperature (TA)
The temperature of the surrounding medium, such as air or liquid, that comes into contact with the device or apparatus.
American National Standards Institute (ANSI)
An organization that compiles and publishes computer industry standards
AMHS
See automated material handling system
Ammonia (NH3)
a colorless, alkaline gas that has a pungent odor. It dissolves readily in water and is combustible. Ammonia is used for the chemical vapor deposition of silicon nitride and for the nitrification of silicon oxide.
Ammonium hydroxide (NH4OH)
A weak base formed when ammonia is dissolved in water
Amorphous silicon
Silicon with no discernible crystalline structure
Analog
A signal in an electronic circuit that takes on a continuous range of values rather than only a flew discrete values ; a circuit or system that processes analog signals.
Analog device
A microcircuit in which the output is a mathematical function of the input
Analytical model
A representation of a process or phenomenon by a set of solvable equations. Contrast simulation.
Ancillary areas
Subordinate or support areas outside the cleanroom
Angle-resolved scattering (ARS)
Technique that measures light scattered from particles as a function of angle; used to characterize particles.
Angstrom(A)
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 A.) The preferred SI unit is nanometers. 10 A=1 nm.
Anion
An ion that is negatively charged
Anion-exchange resin
An ion-exchange resin capable of the reversible exchange of negatively charged ions
Anisotropic etch
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.
Anneal
A high-temperature operation that relieves stress in silicon, activates ion-implanted dopants, reduces structural defects and stress, and reduces interface.
Anodic coating
A protective, decorative, or functional coating formed by conversion of the surface of a metal in an electrolytic oxidation process.
Anoxia
An abnormal condition characterized by a relative or total lack of oxygen ; may be local or systemic.
Antireflective coating (ARC)
A layer of dielectric material deposited on a wafer before resist to minimize reflections during resist exposure.
Antimony
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.
AOQL
Average Outgoing Quality Level - The maximum acceptable reject percentage on the average for all outgoing lots.
Apex chip
On a semiconductor wafer 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.
API
See application programming interface.
Apnea
An absence of spontaneous respiration
Application-level synthesis
Synthesis from specifications described in a style natural to an application area, such as dataflow diagrams for digital signal processing applications.
Application programming interface (API)
A means of invoking services in the code of an application. An API is needed for each interface of any architecture
Application software
The software performing the specific task of the equipment or the host computer
AQL
Acceptable Quality Level - The maximum percent defective that can be considered acceptable as an average for all lots screened. The sample size used with a given AQL will prevent acceptance of 95% of all lots having a greater percent defective
Aqueous extraction
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.
ARC
See antireflective coating
Architecture
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
Area¢?簾岬? contamination
Foreign matter on localized portions of a wafer or substrate surface.
Array
In lithography, an arrangement of repetitive patterns on a die, such as an array of memory cells.
ARS
See angle-resolved scattering.
Arsenic trioxide (As2O3)
A white powder used as a solid source of arsenic for forming n-type regions in semiconductors
Artifact
A physical standard against which a parameter is measured ; for example, a test wafer used testing parametric drift in a machine
Aseptic methods
Methods that minimize contamination of a mineral residue
Ash
To apply heat to a material until the material has been reduced to a mineral residue
Ashing
The operation of removing resist from a substrate by oxidation; a reaction of resist with oxygen to remove the resist from the substrate.
ASIC
Application Specific Integrated Circuit
Aspect ratio
In etch, the depth-to-width ratio of an opening on a wafer.
Asphyxia
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 positions.
Assay
The determination of the content of a specific component with no evaluation of other components
Assignable cause
See special cause
Assist
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.
ASO
See automatic shutoff
Asynchronous
Independent of time-controlled sequence or chronological occurrence
Ataxia
An abnormal condition characterized by impaired ability to coordinate movement
Atmosphere (atm)
A unit of pressure equal to the pressure exerted by a vertical column of mercury 760mm high, at a temperature of 0¢??E,and under standard gravity. One technical atmosphere equals 1kg¢?簾岬?f/¡×ⓒ÷ (14.7 pounds per square inch).
Atomic absorption spectrometry
The measurement of the light absorbed at the wavelength of resonance lines by the unexcited atoms of an element
Atomic percent
In electron spectroscopy for chemical analysis (SECA) of plastic surface composition the number of atoms of a particular element present in every hundred atoms within the ESCA detection volume.
Atomic transfer
In automated material movement, the transfer of a single transfer object from Equipment A directly to Equipment B with only one change in ownership.¢?簾岬? An atomic transfer is the basic unit of movement in automated material movement.
ATP
Acceptable Test Plan - A document developed for the purpose of detailing all of the testing involved in device and/or lot acceptance.
ATPG
See automatic test pattern generation
At-speed test
Any test performed on an integrated circuit that tests the device at its normal operating clock frequency
Attribute
The real-world characteristics or properties of an entity, recorded as part of an entity type
Attributes
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
Attributes data
Gross quantitative data indicating the total number of devices subjected to and passing or failing the various screening steps in a test sequence.
Audit
Random surveillance of processes, specifications, etc
Auger process
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.
Autodoping
In the manufacture of silicon epitaxial wafers, the incorporation of dopant originating from the substrate into the epitaxial layer.
Automated material handing system (AMHS)
Equipment that helps control the flow of material in a manufacturing facility ; e.g., robots, computers, sensors, and protective carriers.
Automated system test
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.
Automatic shut off
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.
Automatic test pattern generation (ATPG)
The automatic development of vectors which, when applied to an integrated circuit, permit faults to be detected in the performance of the integrated circuit.
Automatic valve
A valve with an actuation device that can be operated remotely, such as a pneumatically or electrical controlled valve.
Available equipment capacity
Potential number of product wafers the equipment could process during the equipment uptime period if there were no engineering or standby time allowed.
Average defect count
In optical analysis of surface condition, the result of dividing the total number of defects on a single photomicrography by the capacity to distill without change in composition.
Axis
A plane through a device established for the purpose of orienting the application of force during such stresses as constant acceleration. The most widely used axis is the Y1 axis in which the application of force is such it will tend to lift the die off the mounting surface or the wires off the die.
Alkali
Any compound that has highly basic properties. Alkalis are often hydroxides of alkali metals (metals that belong to group IA of the periodic tale, including Li, Na, K, Rb, Cs and Fr).
Threshold limit value
TLV. The American Conference of Governmental Industrial Hygienists (ACGIH) guideline for the airborne concentration of a material to which nearly all U.S. workers can be exposed day after day without adverse effect.
Gallium Arsenide
GaAs. A semiconductor base material whose high electron mobility has led it to be used in the fabrication of high speed circuits. GaAs circuits are not considered as easy to manufacture as silicon circuits.
Bird's beak
A structural feature produced as a result of the lifting of the edges of the nitride layer during subsequent oxidation
Deionization (DI)
An ion-exchange process in which all charged species or ionizable organic and inorganic salts are removed from a solution.