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GLOSSARY OF TERMS

 

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A/D Converter
Analog-to-Digital converter. A circuit board or integrated circuit that converts analog input signals to digital equivalent-weight output signals.

Acceptor
An impurity from column III of the periodic table, which adds a mobile hole to silicon, thereby making it more p-type and accepting of electrons. Boron is the primary acceptor used to dope silicon. Compare donor.

Aligner
A processing tool used to transfer lithographic patterns from a photomask to a silicon wafer. There are four main types of aligners: contact, proximity, projection, and steppers. See also lithography, mask, and stepper.

Alignment
Positioning of a mask or with respect to the wafer.

Alignment Marks
Location marks on the mask and wafer used to secure proper alignment.

Alloy
(1) A compound composed of two or more metals; or, (2) In semiconductor processing, the alloy step that causes the interdiffusion of the semiconductor and the material on top of it, forming an ohmic contact between them.

ALU
Arithmetic Logic Unit. One of the three essential components of a microprocessor, the other two being data registers and control. The ALU performs addition and subtraction, logic operations, masking, and shifting (multiplication and division).

Aluminum (Al)
The metal most often used in semiconductor technology to form the interconnects between devices on a chip. It can be applied by evaporation or by sputtering.

Amorphous
Materials that possess no obvious arrangement of atoms. Plastics are amorphous. Silicon, prior to being refined for processing, is amorphous.

Analog
A continuous representation of phenomena in terms of points along a scale, that may take any value. Real-world phenomena, such as light, sound, temperature and pressure are analog conditions. See Linear IC.

Analog Array
See Tile Array.

Angstrom
A unit of length. 10,000 angstroms equals 1 micron. 1×108 angstroms equals 1cm. A silicon atom has a lattice spacing of 5.43 angstroms. Symbol: Å. See also micron.

Anisotropic
An etch process that displays little or no undercutting.

Anneal
A relatively cool processing step (among the last in wafer manufacturing) that helps minimize stress in the crystal structure of the wafer.

Architecture
The common logic structure of a family of programmable integrated circuits. The same architecture may be realized in different manufacturing processes.

Arsenic
A Group V element that is an n-type dopant in silicon.

ASCII
American Standard Code For Information Interchange. An eight-bit code for alpha-numeric character transfer adopted by the American Standards Association to achieve universal compatibility among data devices. Pronounced “ask-ee.”

ASIC
Application Specific Integrated Circuit. Semiconductor circuits specifically designed to suit a customer’s particular requirement, as opposed to a DRAM or microcontroller, which are general-purpose parts.

ASP
Average selling price.

Assembly
The step in semiconductor manufacturing in which the device is encased in a plastic, ceramic, or other package. In some cases, the chip is assembled directly on a printed circuit board.

ASSP
Application Specific Standard Product. A standard product that has been designed to implement a specific application function, as opposed to a general-purpose product such as a RAM.

Atomic Number
A number given to an element on the periodic table that corresponds to the number of protons (and therefore, electrons) in the atom.

Atomic Particles
The separate parts of an atom including the electrons, protons, and neutrons.

ATM
Asynchronous Transfer Mode. A method of transmitting voice, data, and video in fixed-sized packets over high-speed telecommunications channels.

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Back End
In semiconductor manufacturing, the package assembly and test stages of production. Includes burn-in and environmental test functions. Compare front-end.

Bandwidth
The width measure of a signal from the lowest to the highest frequency (or bit rate). For analog signals, the width is in the frequency domain, expressed in Hz. For digital signals, the width is in the time domain, expressed in bits per second.

Base
One of the three regions that form a bipolar transistor. It is the control portion of an NPN or PNP transistor. It physically separates the emitter and collector regions. See also collector and emitter.

BEOL
Back End Of Line. The steps of the IC fabrication process where the active components (transistors, resistors, etc.) are interconnected with wiring on the wafer. It includes contacts, insulator, metal levels, and bonding sites for chip-to-package connections. Dicing the wafer into individual integrated circuit chips is also a BEOL process.

BGA
Ball-Grid Array. A packaging technology for high-pin-count packages. Name derived from the array of solder balls at the bottom of the package. The balls are surface-mounted on a printed circuit board. I/O lead counts in the thousands can be achieved with BGA designs.

BiCMOS
Bipolar Complementary Metal Oxide Semiconductor. An IC technology combining the linearity and speed advantages of bipolar and the low-power advantages of CMOS on a single IC.

Binary Number System
A number system employed in computers and digital systems where successive digits are coefficients of powers of the base 2, rather than the base 10. For example, the decimal number 13 is represented by the binary number 1101 (1×23 + 1×22 + 0x21 + 1×20).

Bipolar Transistor
An active semiconductor device formed by two p-n junctions whose function is amplification or switching of an electric current. Bipolar transistors have three sections: emitter, base, and collector.

Bit
BInary digiT. A digit (1 or 0) that is the smallest unit of information recognized by a computer. Used to represent two states in the binary number system. Eight bits equals one byte. Also see binary number system.

Boat
Container (usually quartz, metal, or Teflon) used to carry wafers during the various manufacturing stages.

Boat Puller
A mechanism used to push/pull a load of wafers into or out of a furnace at a controlled speed.

Bond Pad
An area on the periphery of a silicon die for making connection to one of the package pins. A small-diameter gold or aluminum wire is bonded to the pad area by a combination of heat and ultrasonic energy. Connection may also be made to the bond pads using solder balls for flip-chip applications.

Bonded Wafer
A composite dielectrically isolated substrate formed by fusing together (at high temperature) the oxidized surfaces of two individual silicon substrates.

Bonding
The process of connecting wires from the package leads to the chip (or die) bonding pads. Part of the assembly process. A small-diameter gold or aluminum wire is bonded to the pad area by a combination of heat and ultrasonic energy.

Boron (B)
The p-type dopant commonly used for the isolation and based diffusion in standard bipolar integrated circuit processing.

Buried Layer
The N+ diffusion in the p-type substrate done just prior to growing the epitaxial layer. The buried layer provides a low-resistance path for current flowing in a device.

Bus
Four or more parallel conductors in an information processing system along which information is transmitted from one part to another. The microprocessor, peripherals, memory, and other components are interconnected by a common bus.

Bus Driver
An IC added to the bus to facilitate sufficient drive to the CPU when many peripheral devices are tied to the bus. Drivers are needed because of capacitive loading, which slows down the data rate and prevents proper time sequencing of system operation.

Byte
From the expression, “by eights.” A group of eight contiguous bits (binary digits) handled as a unit in computer processing. A byte can store one alphanumeric character.

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CAD
Computer-Aided Design. The use of computer aids (hardware and software) in the electrical and physical design and verification of new things.

CAE
Computer-Aided Engineering. The use of computer aids (hardware and software) in electrical design. See CAD.

CAM
Computer-Aided Manufacturing. The use of computer aids (hardware and software) in planning, tracking, analyzing, and implementing the construction of manufactured items.

Can
A metal package with usually three to five leads that is used to connect a semiconductor circuit to the printed circuit board.

Capacitance
Storage capability of an electrical charge.

Capacitor
A discrete device with the capability of storing a charge on two conductors separated by a dielectric.

CERDIP
Ceramic Dual In-line Package. A package assembled with the leadframe sandwiched between two ceramic layers and sealed with a glass.

CERPACK
Ceramic Package. A cerdip-like package with the leadframe extended out on two or four sides, typically in surface-mounting format. Characteristics similar to CERDIP. Also known as CERPAC or CERPAK.

Channel
The region separating the source and drain of a field-effect transistor. With the application of a voltage to the gate electrode, the conducting properties of the channel are altered, thereby controlling the current across the channel.

Charge Carrier
A carrier of electrical charge, such as an electron or hole, within the crystal of a solid-state device.

Chemical Etching
An acid bath to remove surface damage and to make the silicon crystal slices thinner.

Chemical Mechanical Polishing (CMP)
A process of flattening and polishing a wafer by combining chemical removal with mechanical buffing.

Chemical Vapor Deposition (CVD)
A gaseous process that deposits insulating films or metal onto a wafer at an elevated temperature. Often, reduced pressure is used to promote the chemical reaction.

Chip
Also called a die. Popular term describing a small piece of silicon that contains a complete discrete component or an integrated circuit. Many chips are made on a single wafer, then separated into dice (plural of die) and packaged individually.

Chip Carrier
A low-profile component package, usually, square, whose active chip cavity or mounting area is a large fraction of the package size, and whose external connections are usually on all four sides of the package.

Chip-Level Integration
The combination of two or more integrated-circuit functions and/or technologies on one IC to achieve miniaturization, reduce systems cost, and make new applications possible.

CIM
Computer-Integrated Manufacturing. The integration of computer control and monitoring into a manufacturing process.

Circuit
A combination of electrical or electronic components, interconnected to perform one or more specific functions.

CISC
Complex Instruction Set Computer. Considered the most common CPU architecture of the 1980’s and 1990’s. Includes the x86 and Pentium family of processors. Compare RISC.

Class Number
In cleanroom designs, it refers to the number of particulates in one cubic foot of air. Class 1 means one particulate in a cubic foot of air.

Cleanroom
A confined area for manufacturing ICs in which the humidity, temperature, and particulate matter are precisely controlled. The “class” of the cleanroom defined by the maximum number of particles in one cubic foot of cleanroom space.

CMOS
Complementary Metal-Oxide Semiconductor. A MOS technology in which both p-channel and n-channel components are fabricated on the same die to provide integrated circuits that use less power than those made with other MOS or bipolar processes.

COB
Chip-On-Board. One of many configurations in which a chip is directly bonded to a circuit board or substrate. These approaches include wirebonding, TAB, or flip-chip interconnections.

Collector
One of the three regions that form a bipolar transistor. The base-collector p-n junction is usually reverse-biased so that minority carriers that are injected into the base from the emitter are efficiently extracted into the collector.

Comparator
A device that compares two inputs for equality. One type compares voltages and gives outputs of less than or greater than. Another type compares binary numbers and has outputs of less than, equal to, or greater than. A third compares frequency.

Complementary
A term describing ICs that employ components of both polarity types connected in such a way that operation of either is complemented. A complementary bipolar circuit employs both NPN and PNP transistors. A complementary CMOS circuit (CMOS) employs both n-channel and p-channel devices.

Conductivity
The ability of a material to conduct electricity.

Conductor
Any material, such as aluminum, copper, or gold, that offers little resistance to the flow of electrical current.

Consortium
A combination or group of organizations formed to undertake a common objective that is beyond the resources or capabilities of any single organization. SEMATECH is a consortium.

Contamination
The presence of unwanted particles, chemicals, or other substances.

Converter
See A/D Converter or D/A Converter.

Copper (Cu)
A metal used in semiconductor technology to form the interconnects between devices on a chip. It offers higher performance than aluminum because of its lower resistivity. It can be applied by electroplating.

CPLD
Complex Programmable Logic Device. Programmable logic devices characterized by an architecture offering high speed, predictable timing, and simple software.

CPU
Central Processing Unit. The heart of any computer system. The CPU is made up of data registers, computational circuits, the control block, and I/O (input/output) functions. See microprocessor (MPU).

Crystal
A material in which atoms are arranged in structured groups.

Crystal Defects
Dislocations in a crystal that impact the performance of an electrical signal.

CTE
Coefficient of Thermal Expansion (also called Temperature Coefficient of Expansion, TCE). A parameter used to rate the extent to which a material expands when its temperature is raised or contracts when its temperature is lowered. Thermal stresses occur when a material is constrained during expansion or contraction.

Current
The flow of electrons or holes. Measured (in amps) as the number of particles passing a given point per unit of time. Current can be induced by application of an electric field through a conductor or by changing the electric field across a capacitor.

Custom Integrated Circuit
An IC that requires a full set of masks specifically designed for a particular function or application. A custom IC is usually developed for a specific customer.

Czochralski Crystal Grower
A method of growing a crystal in which a seed is used to pull a crystal from a crucible of molten material.

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D/A Converter
Digital-to-Analog Converter. A circuit that converts digital input signals to analog output signals.

DC-DC Converter
An electrical circuit that changes direct current (DC) from one voltage level to another. Frequently found in battery-operated systems.

DCA
Direct Chip Attach. A packaging technology where a bare die (unencapsulated) is mounted directly to a printed circuit board. The pads on the die may be connected to the PCB using wirebonding, TAB, or flip-chip methods. DCA offers the highest I/O density and smallest space requirements.

Deep UV (DUV)
A wavelength of light that is used to expose photoresist and that has the ability to produce very small image widths.

Defect
A chemical or structural irregularity that degrades the crystal of silicon or of the deposited materials that reside on its surface. Defects can be active impurities that degrade electrical characteristics over time or inactive particulate matter.

Defect Density
The density or number of defects per square centimeter found of a chip.

Deionized Water
Water used in processing that is free of dissolved ions.

Density
A relative measure of the amount of logic, measured in gates, that may be integrated into a single IC. Higher density equates to more gates. Often used interchangeably with complexity.

Depletion Layer
The area in a semiconductor where essentially all charge carriers have been eliminated by the electric field that exists there.

Deposition
The process in which materials are deposited onto a substrate. Usually refers to thin conducting or insulating films used to form MOS gates, capacitors, thin-films resistors, and the interconnect system for an IC.

Design Rule
Minimum feature size used to make a circuit.

Developer
A chemical used to rinse away areas defined in previous masking and exposure phases of wafer processing.

Development
A wafer processing step in which unwanted photoresist is removed from areas predetermined by the masking and exposure steps.

Dice
Two or more die. See die.

Dicing
See scribing.

Die
A single square or rectangular piece of semiconductor material into which a specific electrical circuit has been fabricated. Plural: dice. Also see chip.

Die Bonding
The method of securing the die to a package with conductive adhesives or metal alloys.

Dielectric
An insulator. Localized regions of dielectric materials are used in semiconductor devices to provide electrical isolation between dice, between metal interconnect layers, and between the gate electrode and the channel.

Dielectric Isolation
A fabrication technique by which components in an integrated circuit are electrically isolated from each other by an insulator (dielectric material). DI has proven particularly advantageous for fabricating high-performance analog ICs.

Diffusion
A high-temperature (usually, 850°C to 1150°C) process in which chemical impurities (dopants) selectively enter and move through the crystalline lattice structure of a semiconductor material to change its electrical characteristics.

Digital
Represented in terms of discrete digits, each distinct from the next. A method of representing and manipulating information by switching current on or off. Compare analog.

Digital Integrated Circuit
ICs that process digital information (expressed in binary numbers). The processing operations can be arithmetic or logical (in which the circuit senses certain patterns of input binary information and indicates so by appropriate output binary signals.

Digital Signal Processing
See DSP.

Diode
A two-terminal semiconductor (rectifying) device that exhibits a non-linear current-voltage characteristic. The diode’s function is to allow current in one direction and to block current in the opposite direction. Also see rectifier.

DIP
Dual In-line Package. The most common IC package, which can be either plastic or ceramic. Circuit leads or pins extend symmetrically outward and downward from opposite sides of the rectangular package body.

Discrete Device
A class of electronic components that includes power transistors and rectifiers, each of which contain one active element. In contrast, ICs typically contain hundreds, thousands, or millions of active elements in a single die.

Donor
An impurity from column V of the periodic table, which adds a mobile electron to the conduction band of silicon, thereby making it more n-type. Commonly used donors are arsenic and phosphorous. Compare acceptor.

Dopant
An “impurity” added to silicon that later determines the finished product’s electrical properties called “type” and “resistivity.” Phosphorous and boron are two dopants commonly used in semiconductor manufacturing.

Doping
Intentional introduction of a selected chemical impurity (dopant) into the crystal structure of a semiconductor to modify its electrical properties. For example, adding boron to silicon makes the material more p-type.

Drain
One of the three regions that form a field-effect transistor. Majority carriers that originate at the source and traverse the channel are collected at the drain to complete the current path.

DRAM
A volatile memory chip (memory is lost when the power is turned off) in which the presence or absence of a capacitive charge represents the state of a binary storage element (zero or one). The charge must be periodically refreshed.

Drive-In
Step in wafer processing in which dopants are driven deeper into the wafer material.

DSP
Digital Signal Processing (or Processor). Digital circuits used to enhance, analyze, filter, modulate, or otherwise manipulate standard real-world (i.e., analog) functions, such as images, sounds, radar pulses, and other such signals in real-time.

Dual In-line Package
See DIP.

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E-Beam
Electron beam. Refers to a machine that produces a stream of electrons (electron beam) that can be used to expose photoresists that are sensitive to such beams. E-beam lithography is a direct-write microprinting technique.

ECL Circuit
Emitter-Coupled Logic circuit. ECL circuits use bipolar transistors biased in the active region. They are a very fast high-power digital technology commonly used in logic circuits.

Edge Die
Incomplete or partial die located on the edge of a wafer.

EEPROM
Electrically-Erasable Programmable Read-Only Memory. A non-volatile memory chip (memory is retained when the power is turned off) with the capability of selective erasure of information through special electrical stimulus.

Electromigration
Motion of ions of a metal conductor (such as aluminum) in response to the passage of high current thought it. Such motion can lead to the formation of “voids” in the conductor, which can grow to a size where the conductor is unable to pass current.

Electron
An elementary atomic particle that carries the smallest negative electric charge (1.6 x 10-19 coulombs). Electrons are light in mass (1/1837 of the mass of the hydrogen atom), highly mobile, and orbit the nucleus of an atom.

Electroplating
Deposition of an adherent metallic coating onto a conductive object placed into an electrolytic bath composed of a solution of the salt of the metal to be plated. Using the terminal as the anode (possibly of the same metal as one used for plating), a DC current is passed through the solution affecting transfer of metal ions onto the cathodic surface.

Emitter
One of the three regions that form a bipolar transistor. Under forward bias of the emitter-base p-n junction, the emitter injects minority carriers (electrons or holes) into the base region where they either recombine or diffuse into the collector.

Encapsulation
Term used to describe the packaging of the chip.

Epitaxy
The controlled growth of one material on another. In IC manufacturing, this often means that an n-type epitaxial layer is grown by deposition on a p-type substrate.

EPROM
Erasable Programmable Read-Only Memory. A non-volatile memory chip (memory is retained when the power is turned off) whose contents can be erased by exposure to ultraviolet light.

ESD
ElectroStatic Discharge. Discharge of a static charge on a surface or body through a conductive path to ground. An electronic component may suffer irreparable damage when it is included in the discharge path.

Etch
The process of removing material from a wafer (such as oxides or other thin films) by chemical, electrolytic or plasma (ion bombardment) means.

EUV Lithography
Extreme UV lithography. An experimental method of projecting images with resolution below 130nm using 13nm wavelength radiation from a laser-producing plasma. Formerly called soft X-ray.

Evaporation
A process step that uses heat to change a metal or metal alloy from a solid state to a gaseous one with the result being deposited on the wafer surface.

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Fab
Fabrication. In semiconductor manufacturing, fabrication usually refers to the front-end process of making devices and integrated circuits in semiconductor wafers, but does not include the package assembly (back-end) stages.

Fault
A defect in an IC that can cause a failure during operation. Usually caused by processing defects.

FCIP/FCOB
See Flip Chip.

Feature Size
Minimum width of pattern openings or spaces in a device.

FEOL
Front End Of Line. The first steps of the IC fabrication process where the individual active devices (transistors, resistors, etc.) are patterned in the semiconductor.

FET
Field Effect Transistor. A solid-state device in which current is controlled between source and drain terminals by voltage applied to a non-conducting gate terminal. See also channel, drain, gate, and source.

Flash Memory
A type of non-volatile memory that can be erased and reprogrammed in units of memory called blocks. It is a variation of electrically erasable programmable read-only memory.

Flat Pack
A package having leads that are parallel to the component body. Hermetic flat packs have leads on two or four sides. Plastic flat packs usually have leads on all four sides (plastic quad flat pack).

Flat Zone
The very tightly controlled high-temperature region of a diffusion tube or furnace.

Flip-Chip
Bonding of chips with contact pads, face down, by solder bump connections. If the die is mounted directly to a system’s circuit board, it is termed flip chip on board (FCOB). If the die is mounted to a package substrate, it is termed flip chip in package (FCIP).

Forward Bias
A voltage applied across a rectifying junction with a polarity that provides a low-resistance conducting path. In contrast, reverse bias causes the junction to block normal current. See p-n junction.

FOUP
Front-Opening Unified Pod. A FOUP is a combination 300mm wafer cassette and transport carrier. The sealed front door maintains a portable mini-environment.

Foundry
A wafer production and processing plant. Usually used to denote a facility that is available on a contract basis to companies that do not have wafer fab capability of their own, or that wish to supplement their own capabilities.

FPGA
Field Programmable Gate Array. A class of integrated circuits for which the logic function is defined by the customer using development system software after the IC has been manufactured and delivered to the end user.

Front End
In semiconductor manufacturing, the fabrication process in which the integrated circuit is formed in and on the wafer. Compare back end.

Furnace
Wafer fab equipment found in diffusion area that is used to maintain a region of constant temperature and a controlled atmosphere for processing semiconductor devices.

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GaAs
Gallium-Arsenide. A III-V compound semiconductor material used for making optoelectronic and high-frequency ICs. With a higher electron mobility than silicon, electrons in GaAs can travel at twice the speed of those in silicon.

Gate
(1) The control electrode in a field-effect transistor. A voltage applied to the gate regulates the conducting properties of the channel region; or, (2) The most basic logic element. A combination of transistors which form a circuit that performs a logic function, such as NAND or NOR.

Gate Array
A semicustom IC consisting of a regular arrangement of gates that are interconnected through one or more layers of metal to provide custom functions.

Gate Length
The physical distance between source and drain of a MOS transistor measured on the photomask plate. When determined from the actual transistor characteristic, it is called “effective” gate length.

Gate Oxide
The thin insulating layer between the gate electrode and channel of a MOS transistor.

Germanium
Semiconductor material used in the manufacture of early transistors and of crystal diodes. Also added to silicon transistors to enhance performance (Ge has a higher electron mobility than Si).

Giga or G
A prefix meaning a multiple of one billion (x109). Symbol: G.

Gigabit
Roughly one billion bits, or 1,073,741,824 bits. Symbol: Gb.

Gigabyte
Roughly one billion (1,073,741,824) bytes. Symbol: GB.

Glass Transition Temperature
In polymer or glass chemistry, the temperature corresponding to the glass-to-liquid transition, below which the thermal expansion coefficient is low and nearly constant, and above which it is very high. Symbol: Tg.

Ground Plane
A conductive layer on a package substrate or buried within a substrate that connects a number of points to one or more grounding electrodes.

GSI
Giant-Scale or Giga-Scale Integration. ICs containing more than 1,000,000,000 (one billion) transistors.

Gullwing
A common lead form used to interconnect surface mounted packages to the printed-circuit board.

Hardware
The physical components of a circuit or system, both passive and active. Compare software.

HEPA Filter
High-Efficiency Particulate Attenuator. A filter constructed of fragile fibers in an accordion-folded design that allows a larger filtering area at an air velocity low enough for operator comfort. Permits a filtering efficiency of 99.99 percent.

HF
Hydrofluoric Acid. An acid used to etch silicon dioxide. Usually buffered or diluted before being used.

Hole
A mobile electron vacancy in a semiconductor that acts like a positive electron charge. Under the application of an electric field, holes move in the opposite direction of electrons, thereby producing an electric current.

Hybrid Circuit
(1) A combination of passive and active electrical devices on an insulating substrate to perform a complete circuit function; or, 2) A combination of one or more integrated circuits with one or more discrete components; or, (3) The combination of more than one type of integrated circuit into a single package.

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I/O
Input/Output. Generally refers to the external connections of an IC that tie it to the outside world. Supply pins and control pins are usually not considered I/O.

IC
See Integrated Circuit.

IGBT
Insulated Gate Bipolar Transistor. A four-layer discrete power device that combines the characteristics of a power MOS transistor and a thyristor. IGBTs are usually found in high-voltage circuits (above 300V).

Impurity
In semiconductor technology, a material such as boron, phosphorus, or arsenic added in small quantities to a crystal to produce an excess of electrons (donor impurity) or holes (acceptor impurity). Also called “dopant.”

InP
Indium-Phosphide. A III-V compound semiconductor material used for making optoelectronic and high-frequency ICs. InP has a higher electron mobility than silicon or GaAs.

Input/Output
See I/O.

Insulator
A material that is a poor conductor of electricity or heat, and used to separate conductors from one another or to protect personnel from active electrical devices. Examples: silicon dioxide (glass), silicon nitride, rubber, ceramics, wood.

Integrated Circuit (IC)
An electronic circuit in which many active or passive elements are fabricated and connected together on a continuous substrate (usually silicon). Compare discrete device.

Interconnect
The conductive path (aluminum, copper) required to achieve connection from one circuit element to others in a circuit.

Intrinsic Semiconductor
An element or compound that has four electrons in its outer ring (i.e., elements from Group IV of the periodic table or compounds of Group III and V).

Ion
An atom that has either gained or lost one or more electrons, making it a charged particle (either negative or positive, respectively).

Ion Implantation
A means for adding dopants to semiconductor material. Charged atoms (ions) of elements such as boron, phosphorus, or arsenic are accelerated by an electric field into the material. Useful for very shallow (<1µ) and precise distributions of dopants.

Isotropic Etching
Etching to the side and in the downward direction. See Anisotropic.

ISP
In-system programming. Methodology whereby a complex programmable logic device can be programmed (customized), after having been soldered or plugged into the user system.

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JFET
See junction field effect transistor.

Junction
The interface plane within a semiconductor crystal, at which the number of p- and n-type carriers are exactly equal, with a surplus of p-type on one side of the junction and n-type on the other.

K or kilo
Generally a prefix meaning a multiple of 1,000 (x103). Symbol: K. In digital systems, a symbol for 210 or 1,024.

Kilobit
1,024 bits. Symbol: Kb.

Kilobyte
1,024 bytes (8,192 bits). Symbol: KB. See byte.

Lapping
Process of grinding and polishing a wafer after processing in order to provide a smooth, uniform back and front surface. Also, the process of making the “flat” along one side of the length of the crystal.

Latch-Up
An undesirable phenomenon in which either a PNPN or an NPNP thyristor-type parasitic structure suddenly turns to an “on” state, thereby bypassing or shorting out portions of an IC.

LCC
Leadless Chip Carrier. A surface-mounted package having metallized contacts (terminals) at its periphery. Usually made of ceramic material.

Leadframe
A stamped or etched metal frame, usually connected to the bonding pads of a die by wire bonding, that provides external electrical connections for a packaged electrical device.

LED
Light-Emitting Diode. A semiconductor p-n junction diode that emits light under forward-bias conditions. The wavelength of the emitted light is a function of the semiconductor material.

Library
The collection of representations such as symbol, simulation model, layout abstract, or transistor schematic, used by the different tools in the design system to create or analyze an IC. Inserting the technologies into a design to create efficient circuits.

Linear
(1) Having an output that varies in direct proportion to the input. ; or, (2) A ratio in which a change in one of two related quantities is accompanied by a directly proportional change in the other.

Linear IC
An amplifying-type, analog device with a linear input/output relation, as opposed to a non-linear, digital device, which is either completely “on” or completely “off” over large ranges of input signals. See analog and linear.

Lithography
The transfer of a pattern or image from one medium to another, as from a mask to a wafer. If light is used to effect the transfer, the term “photolithography” applies. See also aligner, mask, stepper, and x-ray lithography.

Logic
Mathematical treatment of formal logic whereby a system of symbols (i.e., AND, OR, and NOT) is used to represent quantities and relationships. A switch/gate has only two states—open or closed—allowing the use binary numbers for solutions to problems.

LSI
Large-Scale Integration. ICs containing roughly between 10,000 and 100,000 transistors.

LTO
Low Temperature Oxidation.

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Majority Carrier
Mobile charge carrier (hole or electron) that predominates in a semiconductor material. Example: electrons in an n-type region.

Mask
A transparent (glass or quartz) plate covered with an array of opaque and transparent patterns used to define the size and shape of circuit and device elements on a wafer. Opaque areas are made of emulsion, chrome, iron oxide, or other materials.

MCM
See multichip module.

Mega or M
A prefix meaning a multiple of one million (x106). Symbol: M.

Megabit
Roughly one million bits, or 1,048,576 bits. Symbol: Mb.

Megabyte
Roughly one million (1,048,576) bytes. Symbol: MB.

Memory
General term for computer hardware that stores information in electrical or magnetic form. Memories accept and hold binary numbers only.

Memory IC
An IC consisting of memory cells and usually including associated circuits such as those for address selection and amplification. A class of integrated circuits that store digital information. Examples: ROM, EPROM, EEPROM, Flash memory, DRAM, and SRAM.

MEMS
Micro-Electro-Mechanical Systems. A manufacturing technology that combines computing/logic circuitry with tiny mechanical devices such as sensors, valves, gears, mirrors, and actuators embedded in semiconductor chips. The mechanical devices are processed with same materials and methods used to make ICs.

Metallization
The process of depositing a thin film of conductive metal onto a substrate and patterning it to form the desired interconnection arrangement. Metal layers are usually 1µ to 2µ thick in ICs, but several times thicker for power devices.

Micro
A prefix meaning one-millionth (x10-6). Synonymous with micron. Symbol: µ. See micron.

Microcomputer
(1) A computer system whose processing unit is a microprocessor; or, (2) A microprocessor, complete with stored program memory—read-only memory (ROM), random-access memory (RAM), and input/output (I/O) logic on a single chip.

Microcontroller
A single-chip microcomputer with on-board program ROM and I/O that can be programmed for various control functions.

Micron
One-millionth (x10-6) of a meter, or about 40 millionths of an inch. A micrometer. Symbol: µ.

Microprocessor
(1) A central processing unit (CPU) fabricated on one or more chips, containing the basic arithmetic, logic, and control elements of a computer that are required for processing data; or, (2) An IC that accepts coded instruction, executes the instructions received, and delivers signals that describe its internal status. The instructions may be entered or stored internally. Also called MPU (microprocessor unit).

Mil
One-thousandth of an inch (x10-3 inches). Equal to 25.4 microns.

Miller Indices
A numerical system of three numbers used to identify the orientation of planes in a crystal.

Milli
Prefix meaning one-thousandth (x10-3). Symbol: m.

MIPS
Million Instructions Per Second.

Mixed-Signal IC
An integrated circuit that has both digital and analog functions on the same semiconductor chip, permitting a high degree of system integration. Mixed-signal ICs can be optimized for analog, digital, or power functions.

MMIC
Monolithic Microwave Integrated Circuit. Combining active elements (diodes and transistors) with passive elements (resistors, capacitors inductors, and transmission lines) on a single GaAs substrate. Replacement for “chip and wire” microwave circuits.

Mobility
The velocity of a charged particle attained under the action of an applied electric field.

Molecular Beam Epitaxy (MBE)
An evaporative deposition process capable of extreme control of the deposition process.

Molecule
Smallest quantity of a substance that retains the properties of that substance.

Monochromatic Light
Light of a single wavelength.

Monolithic Circuit
Same as integrated circuit. A circuit fabricated within a single body of semiconductor material. This single body of material is referred to as an integrated circuit die. Compare hybrid circuit.

MOS
(1) Metal Oxide Semiconductor; or, (2) A wafer process for fabricating MOSFET devices in either IC or discrete form. See MOSFET.

MOSFET
Metal Oxide Semiconductor Field Effect Transistor. A type of field-effect transistor that functions when a controlling gate voltage is applied to the channel region across an oxide insulating material. Advantages: low power and process simplicity.

MPU
Microprocessor Unit. Used synonymously with microprocessor. See microprocessor and CPU.

MSI
Medium-Scale Integration. ICs containing roughly between 100 and 10,000 transistors.

Multichip Module (MCM)
A hybrid-type package containing a number of integrated circuits and other components. Used instead of printed circuit boards for applications calling for very high packing densities, high frequencies, and high operating speeds.

Multiplexer (mux)
A device that combines several input signals into a single output signal in such a manner that each of the input signals subsequently can be recovered.

Multiplier
A circuit whose output state is the arithmetic product of two input signals. Important in DSP (digital signal processing) technology for signal processing and power control applications.

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N-Type
Silicon doped with phosphorous becomes a substance with loosely held electrons. This is called n-type silicon.

N-Type Semiconductor
A semiconductor type in which the density of holes in the valence band is exceeded by the density of electrons in the conduction band. N-type behavior is induced by the addition of donor impurities such as arsenic or phosphorous to the silicon crystal.

Nanometer (nm)
One-billionth (x10-9) of a meter, or about 40 billionths of an inch. Symbol: nm.

Nanosecond (ns or nsec)
One thousandth of a microsecond, one billionth of a second (1×10-9 seconds). Electronic signals travel approximately one foot per nsec.

Nitrogen (N2)
An inert gas used in semiconductor manufacturing that seldom reacts with other materials. Often used as a carrier gas for chemicals during various processing steps.

NMOS
N-channel MOS. A MOSFET in which electrons are the dominant charge carrier in the semiconductor channel. The channel is n-type. NMOS devices run at least twice as fast as PMOS devices because the mobility of electrons is higher than that of holes.

Noise
Unwanted acoustic or electromagnetic disturbances, as opposed to desired signals. See signal.

Non-Volatile (Memory)
Any device that retains its stored information after power is removed. Examples: EPROMs, flash memory, rotating magnetic discs, optical memory. Compare volatile memory.

NPN Transistor
A two-junction transistor with an n-type collector and emitter and a p-type base. See bipolar transistor and complementary. Compare PNP transistor.

NRE
Non-Recurring Engineering. A one-time charge for photomask development, test, and prototype tooling, and associated engineering costs.

Ohm’s Law
Relationship between resistance (R), voltage (V), and current (I). V=IR.

Op Amp
Operational Amplifier. A general purpose device used as a basic building block for implementation of linear functions. Op amps form the “front end” or sensory apparatus of electronic systems, capturing weak signals and amplifying them for processing.

Optical Coupler
A device designed to transfer an electrical signal by utilizing light waves to provide coupling with electrical isolation between input and output. Sometimes called photocoupler.

Optoelectronic Device
A device that is responsive to or that emits or modifies light waves. Examples are LEDs, optical couplers, laser diodes, and photo detectors.

Over-Voltage
A voltage in excess of the normal operating voltage of a device or circuit. See ESD and over-voltage protection.

Over-Voltage Protection
A term used to describe the built-in capability of an electrical circuit to dissipate or shunt electrical impulse energy at a voltage low enough to ensure the survival of circuit components.

Oxidation
Growth of oxide on silicon when exposed to oxygen. The thickness of the oxide is largely time and temperature dependent.

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P-N Junction
The basic structure formed by the intimate contact of p-type and n-type semiconductors. The important characteristic of a p-n junction is that it will conduct electric current with one polarity of applied voltage but not with the opposite polarity.

P-Type
Silicon doped with acceptor impurity (III) such as boron (p-type silicon).

P-Type Semiconductor
A semiconductor type in which the density of electrons in the conduction band is exceeded by the density of holes in the valence band. P-type behavior is induced by the addition of acceptor impurities, such as boron, to the crystal structure of silicon.

Package
The sealed, protective container that houses an electronic component or die. External terminals provide electrical access to the components inside. Packages provide for power and signal distribution, power dissipation, and protection of the circuits.

Parametric Tests
Tests that measure electrical performance of a chip such as maximum current, leakage, and output drive.

Parasitic Extraction
Applies to software that analyzes a layout database and determines the capacitance (and sometimes resistance) of the metal interconnections.

Passivation
A layer of insulating material deposited over a wafer or a region of a device to stabilize and protect the surface against moisture, contamination, and mechanical damage. Silicon dioxide or silicon nitride are often used for IC passivation.

Passive Component
An electrical component without gain or current-switching capability. Commonly used when referring to resistors, capacitors, and inductors.

PBX
Private Branch Exchange. A telecommunications switching facility or service located on the customer’s premises.

PC
Personal Computer. Also an acronym for Production Control in a manufacturing organization. Can also refer to Printed Circuit when referencing printed circuit boards (PCBs).

Peta
A prefix meaning a multiple of 1015.

PG Tape
Pattern-Generation Tape. Computerized instructions used to build photomasks.

PGA
Pin-Grid Array. A packaging technology for high-pin-count packages. Name derived from the array of pins at the bottom of the package. The pins go through holes in a printed circuit board. I/O lead counts as high as 600 can be achieved with PGA designs.

Phosphine (PH3)
A gas often used as a source of phosphorus for doping silicon.

Phosphorus (P)
N-type dopant commonly used for the emitter diffusions in standard bipolar IC technology.

Photomask (Mask)
A glass photographic plate that contains the circuit pattern used in the silicon-chip fabrication process.

Photocoupler
See optical coupler.

Photolithography
Lithographic techniques involving light as the pattern transfer medium. See lithography.

Photoresist
A light-sensitive chemical used to coat the wafer. When developed and removed by processes similar to those used in photography, the exposed photoresist adheres strongly to the chip and the unexposed portion is etched away, forming a circuit pattern.

Pinhole
A small undesired hole in the photoresist or in the opaque region of a mask or reticle.

Pitch
The center-to-center spacing between pads, rows of bumps, pins, posts, leads, etc., on an IC or circuit board.

Place and Route
The act of placing the physical representations of the circuit functions, whether as macro blocks or as rows of standard cells. The signal paths are then routed on the interconnect layers.

Plasma Etching
Dry-etch of electrical circuits done with high-energy gas made up of ionized particles containing fluorine or chlorine. Alternative to etching with wet chemicals.

PLCC
Plastic Leaded Chip Carrier. A leaded quad package—a replacement for the plastic DIP in surface-mount applications. External connections consist of leads around all four sides of the package.

PLD
Programmable Logic Device. A digital IC that can be programmed by the user to perform a wide variety of logical operations.

Plug (Via Plug)
A metal deposited in a connecting via hole. The metal interconnect plugs provide linkage between the conducting layers of a multilayer-metal IC device.

PMOS
P-channel MOS. A type of MOSFET where the semiconductor channel is doped p-type. In such a MOSFET, the current between source and drain is primarily due to the motion of holes. Compare NMOS.

PNP Transistor
A semiconductor junction transistor with a p-type collector and emitter, and an n-type base. Current amplification arises from the injection of holes from the emitter into the base, and their subsequent collection in the collector.

Polycrystalline Silicon (Poly)
Silicon composed of many crystal unit cells randomly arranged.

Polymer
A complex organic chemical compound made up of repeating units.

Power Control Circuit
System power supply control functions and output drive, allowing electronic systems to do actual work for such diverse applications as motors, video, and computer disk drives.

Power Discrete
See discrete device and power transistor.

Power MOSFET
A MOSFET circuit capable of handling current ratings of more than 1 ampere.

Power Transistor
A transistor capable of being used at current ratings of more than 1 ampere.

PQFP
Plastic Quad Flat Pack. A type of plastic package that has leads on all four sides.

Printed Circuit
A circuit in which the wires or components have been replaced by a conductive pattern printed upon or bonded to the surface of an insulating board.

Projection Alignment
An exposure system whereby the image on a mask or reticle is projected onto the wafer. For LSI and VLSI, projection alignment is standard.

PROM
Programmable Read-Only Memory. A read-only memory that can be written to only once. Programmed after manufacture by external equipment. Typically, PROMs utilize fusible links that may be burned open to set a specific memory location to a logic level.

Proximity Aligner
An aligner tool that holds the wafer and mask or reticle a small distance apart during the resist exposure cycle.

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QML
Qualified Manufacturer’s List per military standard.

Quality Control
A term denoting the functions or collection of duties that must be performed in order to carry out a company’s quality objective.

Quartz
Commercial name for silicon dioxide formed into glass products. It features high temperature resistance, making it an ideal material for use in the semiconductor manufacturing process.

Rad
Specifies the amount of energy transferred to a material by ionizing radiation. The material must be specified because the energy differs with each material.

Rad-Hard
Radiation Hardened. See radiation hardened circuit.

Radiation Hardened Circuit
IC that has been manufactured with special devices and isolation techniques such that when exposed to heavy radiation, it remains operational. Otherwise, the radiation generates electrical currents inside the semiconductor material, shorting it out.

RAM
Random Access Memory. A memory that may be written to or read from any address location in any sequence. Random access in the sense of providing access to any storage location in the memory. See DRAM and SRAM.

Rapid Thermal Oxidation (RTO)
An oxidation process performed in a rapid thermal processing (RTP) tool.

Rapid Thermal Processing (RTP)
A single-wafer processing tool that uses high intensity lights or other sources to heat and cool the wafer in milliseconds.

RCA Clean
A multiple-step process to clean wafers before oxidation. Named after RCA, the company that developed the procedure.

Reactive Ion Etching (RIE)
An etching process that combines plasma and ion beam removal of the surface layer.

Reactor
Equipment piece used to deposit a layer of material used in semiconductor processing.

Real-Time Operation
Data processing techniques in which information is utilized as events occur and the information is generated, as opposed to batch processing at a time unrelated to the time the information was generated.

Rectifier
A device that converts alternating current into direct current. See diode.

Resistivity
A measure of the resistance to current flow in a material.

Reticle
A photomask used in a stepper. See mask, photolithography, and stepper.

RISC
Reduced Instruction Set Computer. A type of processor architecture that processes programs more quickly than conventional microprocessors because it uses a smaller, less complex set of instructions. Compare CISC.

ROM
Read-Only Memory. A memory in which the binary information located at each address is fixed and cannot be changed subsequently. Permanently stores information repeatedly used, such as tables of data, characters for electronic displays, etc.

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Scanning Electron Microscope (SEM)
Microscope used to magnify images as much as 50,000 times by means of scanning with an electron beam.

Schematic Capture
The capture of circuit design by graphical means. The symbols representing functional blocks or individual circuit elements are placed on a graphical design workstation and interconnected by graphical representations of wires, pins, etc.

SCR
Silicon Controlled Rectifier. A type of thyristor that is designed for forward bias, power switching, and control. See thyristor.

Scribe and Break
The procedure used to separate a processed wafer into individual ICs. Narrow channels between each IC are mechanically weakened by scratching with a diamond tip scribe or saw or burning with a laser until the wafer is broken into individual ICs.

Scribing
The means whereby individual chips are cut from the wafer at the completion of the manufacturing process.

SEMATECH
Semiconductor Manufacturing Technology research consortium located in Austin, Texas.

Semiconductor
An element (e.g., silicon and germanium) whose electrical conductivity lies between that of conductors (copper) and insulators (glass). Has relatively high resistance in a pure state and much lower resistance when small amounts of impurities are added.

Semiconductor Device
An electronic device whose essential characteristics are governed by the flow of charge carriers within a semiconductor.

Semicustom IC
An integrated circuit in which a portion of the circuit function is predefined and unalterable, while other portions can be configured to meet the designer’s specific needs. Semicustom ICs can be analog, digital, or mixed-signal.

Sensor
A component that provides an electrical signal in response to a specific physical or chemical stimulus such as heat, pressure, magnetic field, or a particular chemical vapor.

SiGe
Silicon-Germanium. A semiconductor technology in which a small amount of the material germanium is added to silicon transistors in order to enhance the frequency performance of silicon-based ICs. Germanium has a higher electron mobility than silicon.

Signal
Any electronic visual, audible, or other indication used to convey information. In semiconductors, an electrical quantity (typically voltage, current, or light level) corresponding to some physical quantity.

Signal Processing
A broad class of electronic functions that enhance the representations of physical or electrical phenomena. Temperature, pressure, vibration, acceleration, and flow are examples of physical properties that rely on signal processing enhancements.

Silicon
A solid element (number 14 on the periodic table) that is abundantly available in the form of SiO2. Its extreme abundance, moderate processing temperatures, and the stability of its native oxide make it the preferred semiconductor material.

Silicon Dioxide (SiO2)
A nonconducting layer that can be thermally grown or deposited on wafers. Thermal silicon dioxide is commonly grown using either oxygen or water vapor at temperatures above 900°C.

Silicon-On-Insulator
See SOI.

Simulation
The process of using software to model an electronic system.

Single Crystal
Substances that have all unit cells arranged in a definite and repeated fashion as opposed to polycrystalline materials, which have unit cells randomly arranged.

SIP
Single In-Line Package. A package having a single row of external leads, usually mounted vertically with leads through the PC board, but can be surface mounted with leads bent in gull-wing fashion.

SLIC
Subscriber Line Interface Circuit. An IC widely used as an interface in telephone networks.

Slice
(1) noun. Another term for wafer; or, (2) verb. To cut into wafers. In semiconductor technology, to cut a crystalline ingot into thin pieces (wafers or slices) upon which the device patterns are subsequently formed.

SLICE
Simulation Language with Integrated Circuit Emphasis. For the design of the analog portions of mixed-signal circuits, it is a BASIC-like language that is coupled with standard language constructs such as looping and arrays to call other simulators.

SMIF
Standard Mechanical Interface. A system that allows the mating of portable clean wafer boxes (called pods) to the clean microenvironment loading stations of process tools.

SMT
Surface-Mount Technology. The mounting of components on the surface of a printed circuit board, as contrasted with through-hole mounting where component leads extend through the board.

Soft Baking
A heating process used to evaporate a portion of the solvents in photoresist.

Software
The changeable programs and instructions for a computer, as opposed to the fixed hardware that implements the programs.

SOI
Silicon-On-Insulator. A composite structure consisting of an active layer of silicon deposited on an insulating material. The insulator can be sapphire (as in SOS), silicon dioxide, silicon nitride, or even an insulating form of silicon itself.

SOIC
Small-Outline Integrated Circuit. A miniature plastic flat pack designed for surface mount with gullwing leads. See SOP.

Solderability
The ability of a conductor to be wetted by hot solder and to form a strong low-resistance bond with the solder.

Solid State
Refers to the electronic properties of crystalline (generally semiconductor) material—as opposed to vacuum and gas-filled tubes. Solid state devices involve the interaction of light, heat, magnetic field, and electric currents in crystalline materials.

SOP
Small Outline Package. Similar to a miniature plastic flat pack, but with gull-wing leadforms primarily or wholly constructed for surface mounting. Also called an SO package.

SOS
Silicon-On-Sapphire. A type of SOI technology in which a layer of silicon is epitaxially grown on a sapphire wafer, with specific regions subsequently etched away between individual transistors. Each device is thus totally isolated from other devices.

Source
One of the three regions that form a field-effect transistor. Majority-carriers (electrons in an n-channel FET or holes in a p-channel FET) originate at the source and flow across the channel to the drain.

SPC
Statistical Process Control. A technique to ensure that a manufacturing process is controlled within the limits of its capability.

SPICE
Simulation Program with Integrated Circuit Emphasis. Simulator used to model electrical circuits at the transistor level.

Spin Rinse Dryer
A machine that automatically rinses and dries wafers by spinning them about a central axis.

Spinning
A technique used to evenly coat photoresist onto a wafer. Spinning results in a 0.5µ layer of photoresist being applied with no more than 10 percent variation across the wafer.

Sputtering
A means of depositing a thin film of material on wafer surfaces.

SRAM
Static Random Access Memory. A read/write memory in which the data are latched and retained. SRAMs do not lose their contents as long as power is on. This memory does not need to be refreshed as does DRAM.

SSI
Small-Scale Integration. ICs containing less than 100 transistors.

Step Coverage
The ability of new layers to evenly cover steps formed in the existing wafer layers.

Stepper
Aligner used to transfer a reticle pattern onto a wafer. With its limited field of view, low throughput, and high cost, such equipment is usually used only for features size smaller than 1.5µ, where resolution and line-width control are critical.

Storage
Off-line information retention. See memory.

Stripper
Solvent used to remove photoresist.

Substrate
The underlying material on which a microelectronic device is built. Such material may be electrically active, such as silicon, or passive, such as alumina ceramic.

Superconductivity
The flow of electric current with negligible resistance in certain metals and alloys and over certain temperature ranges.

Switch
Pertaining to semiconductors, an analog IC (typically CMOS) which, on command, either passes or blocks an electrical signal.

Switched Capacitor
A technique commonly used in analog signal processing to create filtering and signal conditioning circuits.

System
An integrated whole that is comprised of diverse interacting, specialized structures and sub-functions. A collection of people, machines (hardware), and software organized to accomplish a set of specific functions.

System-Level Integration
(1) In semiconductor design and fabrication, packing an increasing number of devices into an IC or designing MCMs that are increasingly complex; or, (2) In electronics in general, the progressive linking and testing of system components into a complete system. See multichip module.

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TAB
Tape Automated Bonding. A chip-to-package connection process in which the package leads are formed on a flexible tape and all the lead fingers are bonded to the chip in a single operation.

TAM
Total Available Market. Used to show actual dollars spent in a market.

Telecom
Telephone Communications. See SLIC.

Tera or T
A prefix meaning a multiple of one trillion (x1012). Symbol: T.

Test Die
Die on a wafer that appear to have a different pattern from most others, but are designed on a larger scale to allow in-process quality control.

Test Program
The total computer code that instructs automatic test equipment exactly how the integrated circuit is to be tested.

Test Vector
A string of binary digits applied to the input of a circuit and simultaneously used for testing the outputs.

Test Vehicle
A full functional product or an array of test devices and structures used to develop process integration and control.

Testability
A descriptor of a general area of circuit design that deals with how testable a particular circuit design is going to be. Specific implementation of structures and test methods can make circuits more testable provide better testability.

Thermal Oxide
For silicon semiconductors, oxide generated by exposing the silicon to oxygen at high temperatures. The resulting interface has low levels of ionic impurities and defects.

Thermocouple
A tool that measures the temperature in a furnace of a reactor. Heat generates a voltage between two wires that is proportional to the temperature.

Thyristor
A family of semiconductor devices that exhibit bi-stable current-voltage characteristics and can be switched between a high-impedance, low-current “off” state and a low-impedance, high-current “on” state. Primarily used for power switching applications.

Tile Array
Primarily used in analog ASIC design styles. A pre-established layout of electrical devices that can be configured to create a number different electrical functions by means of programming the levels of interconnect material.

Total Dose
Term used to describe the total exposure of an IC to ionizing radiation, typically gamma rays, energetic electrons, or x-rays.

Transient Over-Voltage
A condition in electrical circuits resulting from a sudden release of energy. Often this condition is precipitated by a static discharge, lightning, or switching of an inductive load. May occur in repeated fashion or randomly. See over-voltage.

Transient Radiation
A pulse of ionizing radiation. Transient radiation can cause data upset, device latchup, and destruction of unprotected ICs. Properly designed ICs however, can resist such effects to high levels of transient radiation.

Transient Suppression
See over-voltage protection.

Transistor
A three-terminal active semiconductor device that serves as a switch or provides current amplification. Comprised of a base, emitter, and collector (bipolar transistor) or gate, source, and drain electrodes (field-effect transistor). Invented by Shockley (Bell Labs) in 1947.

TTL
Transistor-Transistor Logic. A bipolar technology used for producing logic gates. See gate.

Tube
A cylindrical piece of quartz with fitting on one or both ends. It is placed in a furnace to provide a contamination-free and controlled environment for processing wafers.

TVS
Transient Voltage Suppressor. A general category of devices that protect other electronic circuits, components, or systems from destructive transient voltage spikes.

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UHF
Ultra High Frequency. The portion of the radio spectrum between 300 and 3,000 megahertz (MHz). This includes television channels 14 through 83, as well as most radar use.

ULSI
Ultra Large-Scale Integration. ICs containing roughly between 1,000,000 (one million) and 1,000,000,000 (one billion) transistors.

Ultraviolet (UV) Light
Segment of the electromagnetic spectrum from 250 to 500 nanometers. High-pressure mercury sources emit UV light for photoresist exposure.

Undercutting
See isotropic etching.

UNIX
A computer operating system. It is an open architecture meaning that application programs are more easily ported between different versions of Unix than between any other proprietary operating systems.

Vacuum
A low-pressure condition.

Varistor
From “variable-resistor.” A non-linear, voltage-dependent device whose electrical behavior provides transient suppression performance. The device absorbs the potentially destructive energy of incoming transient pulses, thereby protecting the circuits.

VHF
Very High Frequency. The portion of the radio spectrum between 30 and 300 megahertz (MHz). This includes television channels 2 through 13, the FM band, and other commercial communication bands.

Via
Vertical opening filled with conducting material used to connect circuits on various layers of a device to one another and to the semiconducting substrate.

VLSI
Very Large-Scale Integration. ICs containing roughly between 100,000 and 1,000,000 transistors.

Volatile Memory
A memory device that does not retain stored information when power is interrupted. See non-volatile.

Voltage
The force applied between two points causing charged particles (and therefore, current) to flow.

Voltage Regulator
A circuit (either an IC or a portion of an IC) whose purpose is to make the output voltage less variable than the input voltage. For example, a voltage regulator might provide output of 5V +/-2 percent to a logic board from an input of 5V +/-50 percent.

Wafer
A thin slice, typically 10-30 mils thick, sawed from a cylindrical ingot of bulk semiconductor material (usually silicon), typically four to eight inches in diameter, on which many chips are fabricated at one time during the manufacturing process.

Wafer Fabrication
The series of steps used to build an IC or device in and on a wafer.

Wafer Flat
Flat area(s) ground onto the wafer’s edge to indicate crystal orientation of the wafer and for general alignment of wafers through various pieces of equipment. Only used on wafers up to 150mm in diameter. Larger wafers (e.g., 200mm and 300mm) use a small notch instead.

Wafer Sort
Following wafer fabrication, a test to determine the electrical parameters and functionality of the integrated circuits. Each die site of a completed wafer is tested. Die that fail the tests are marked with an ink spot and separated from good die.

Wirebonding
An assembly step in which thin gold or aluminum wires are attached between the die bonding pads and the lead connections in the package. There are three basic wirebonding methods: thermal compression, ultrasonic, and pulse.

WLP
Wafer-Level Packaging. A method for packaging semiconductors in which the first-level interconnections and package-I/O terminals are formed on the chips before the wafer is diced. Unlike for other types of packaging methods, WLP costs decrease on a per-die basis as the number of dice per wafer increases.

X-ray Lithography
The lithographic process for transferring patterns to a silicon wafer in which the electromagnetic radiation used is x-ray, rather than visible radiation. The shorter wavelength for x-rays extends the useful range of lithography.

Yield
The percent of wafers, dice, or packaged units leaving a process as compared to the amount of product that entered that process. The most common yields in the manufacturing process are: wafer fab yield, probe yield, assembly yield, and final test yield.

Zener Diode
A semiconductor p-n junction diode that has a controlled reverse-bias breakdown voltage, and is used to supply a specific voltage for other protected components.

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Sources: Intersil, Xilinx, IC Insights


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