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Vocabulary List - Provided by Integrated Circuit Engineering Corporation 1999 - it is not a definitive list; but a resource reference.

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A

Acceptor
An impurity that can make a semiconductor P-type by causing the absence of electrons in the conduction band (called "holes"). These "holes" are carriers of positive charge. See donor.

Actinic
The property of radiant energy, especially in the visible and UV spectral regions, by which chemical changes are produced.

Active Component
A (non-mechanical) circuit component that has gain or switches current flow, such as a diode, transistor, etc.

Aligner
An optical system used in transferring a mask or reticle image to a wafer.

Alignment
The arranging of a mask and wafer in correct positions with respect to each other. After alignment, radiation-sensitive photoresist on the wafer is exposed by radiation passing through the non-opaque areas of the mask.

Alignment Mark
A reference mark used in the alignment of the several photomask layers required for a single device or circuit.

ALSTTL
Advanced LSTTL. A fast bipolar logic family with power dissipation about half that of LSTTL.

Alloy
(1) In semiconductor processing the alloy process step refers to a heat treatment used to improve the metallurgical interaction between the silicon substrate and the interconnect metals. This improves ohmic contact.

(2) Metallurgically is used to mean the blending together of two or more metals to form a particular compound.

Alternating Current
Electrical current that reverses (or alternates) at regular intervals. Abbreviated AC.

Aluminum (Al)
The metal often used in semiconductor technology to form the interconnects between devices on a chip. It is usually deposited by evaporation or sputtering. Aluminum may also be used as a P-type dopant.

Amorphous
An atomic structure having no definite or recognizable form.

Amplifier
A device that uses an active component to increase the voltage or power of a signal without distorting its waveshape.

Analog
A continuous, non-digital representation of phenomena. An analog voltage, for example, may take any value.

AND Gate
A gate whose output is ON only if all input signals are ON.

Angle of Incidence
Angle between the incident ray of light and a normal drawn to the point of reflection.

Angle of Reflection
Angle between the ray of light and the normal drawn to the point of refraction.

Angle of Refraction
Angle between the refracted ray of light and the normal drawn to the point of reflection.

Angstrom ()
A unit of length. 1/10,000 of a micrometer (10-4m).

Anisotropic
In a subtractive process, the material is removed only in the vertical direction in such a way that the side of the cut is perpendicular to the bottom of the cut.

Anneal
To heat a material to some elevated temperature to reorder the crystal structure and remove stresses. The subsequent cooling schedule affects the final level of stresses.

Annular Illumination
Light source for the reticle, shaped like a ring or annulus centered on the optical axis of the stepper lens.

Antimony (Sb)
An N-type dopant often used to form the buried layer in a bipolar structure.

Antireflective Coating
A coating applied to a surface to reduce reflectivity.

Array
A group of items (elements, leads, bonding pads, circuits, etc.) arranged in rows and columns.

Arsenic (As)
An N-type dopant often used to form the buried layer in a bipolar structure. Also used as an implant source in both bipolar and MOS processing.

Ashing
A method of stripping photoresist by a plasma (an electromagnetically-excited reactant gas).

ASIC
(Application Specific Integrated Circuit) An IC designed to meet a specific customer requirement.

Aspheric Surface
A lens or mirror surface that is altered slightly from spherical to reduce aberrations.

Assembly
The final stage of semiconductor manufacturing, where the active device is encased in a plastic, ceramic or metal package. Also referred to as "back-end" processing.

ASSP
Is a device or chip set with an application specific design (similar to ASIC's) however, the program is used by a large volume of customers for common applications (ie video, core logic, disk storage, etc.).

Atmospheric Oxidation
The process of oxidizing silicon with some species of oxygen in a process tube at atmospheric pressure.

Atmospheric-Pressure Chemical Vapor Deposition (APCVD)
A method used to deposit a thin-film layer in which the process chamber is maintained at atmospheric pressure during the deposition. (Also see CVD).

Atomic Number
A number assigned to each element that identifies the number of protons in the nucleus of an atom.

Audio/Video ASSP's
(Multimedia) are dedicated to high quality images, motion and sound. They also conform to MPEG, JPEG and CCITT Standards.

Autodoping
Atoms that outgas from a material and then are reabsorbed into the process ambient and materials.

Automation
The art of making processes or machines self-acting or self-moving. Also pertains to the technique of making a device, machine, process or procedure more fully automatic.

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BTAB
(Bumped Tape Automated Bonding). A bonding process using inverse beams with solder (or other) bumps on the beams instead of on the chips. Obviates the need for special bumped chips.

Ball Grid Array (BGA)
A method of packaging electronic components and IC's where the electrical connection from within the package is terminated on the outer surface of the package using a solder alloy in the shape of a partial sphere.

Ball Bonding
See Bonding, Ball

Barrier Metal
A metals system used to make ohmic contact to silicon and isolate the silicon substrate from the primary metal used for interconnecting the circuit elements.

Base
The control portion of a bipolar transistor. In an NPN transistor, the P-type material forms the base.

Base Diffusion
The diffusion during which the base regions of transistors are formed.

Batch
A number of wafers processed as a group.

Bath Tub Curve
A graphical representation used to illustrate the failure rate of semiconductor devices.

Beam Leads
Thick, strong leads deposited directly on an integrated circuit chip and used for interconnecting the circuit into the system.

Beam Tape
Polyimide tape supporting copper foil shaped into beam leads for TAB bonding. Specifically designed for in-line automation of IC packaging.

Binary
A system of numbers using 2 as a base, in contrast to the decimal system which uses 10 as a base. The binary system requires only two symbols: 0 and 1.

Bipolar
An electronic device whose operation depends on the transport of both holes and electrons.

BiCMOS
Device having bipolar and CMOS transistors.

Bit
A binary digit. A bit is the smallest unit of storage in a digital computer, and is used to represent one of the two states in the binary number system.

Boat
A wafer holder made from quartz or polycrystalline silicon for use in furnace operations of semiconductor fabrication. Also may be made of Teflon for transporting wafers between processing locations.

Boat Puller
A electro-mechanical device interfaced to the oxidation/diffusion furnaces for inserting or removing at a given rate a number of boats loaded with wafers.

BOE
(Buffered Oxide Etch). A hydrofluoric acid (HF) and ammonium fluoride (NH4F) solution used to etch silicon dioxide.

Bonding, Ball
A thermal compression bonding technique used only with gold wire. The wire end is melted to form a ball, which provides a larger area of contact than otherwise possible.

Bonding, Die
Attaching of the semiconductor die to the package substrate, with epoxy adhesives, gold eutectic or solder alloy. Also called die attachment.

Bonding Pads
Comparatively large metallization areas usually placed around the perimeter of the integrated circuit die to provide the areas to which wires from internal terminations of the leads of the package are connected.

Bonding Wedge
A form of thermal compression bonding used for microelectronic assembly, so named because the bond shapes the wire in a wedge shape.

Bonding Wire
Fine wires, usually aluminum or gold, connecting the metal bonding pads on an integrated circuit to the internal terminations of the leads of the package.

Boolean Algebra
A logical calculus named for mathematician George Boole, using alphabetic symbols to stand for logical variables, and 0 and 1 to represent states. AND, OR, and NOT are the three basic logic operations in this algebra. NAND and NOR are each combinations of two of the three operations.

Boron (B)
The P-type dopant commonly used for the isolation and base diffusion in standard bipolar NPN IC processing, and source/drain regions in PMOS transistors.

Boron Trichloride (BCl3)
A gaseous mixture of boron and chlorine. The mixture is used as a dopant source for P-type diffusions and as an etchant gas for etching aluminum and aluminum alloys.

Boule
A term used to describe the single-crystal silicon mass after the crystal growing process. Also called ingot.

Brazing
The process of joining two or more metals by partial fusion with a layer of hard soldering alloy at high temperatures.

Breakdown (Junction)
A high carrier conduction condition arrived at as a result of the field (voltage) being sufficient to cause this high level of conductance.

Bubbler
A container holding a liquid through which some type of inert carrier gas is passed to carry some partial pressure of the liquid into a process tube or a reaction chamber.

Bumped Chip
A chip from a wafer that has been specifically processed with buffer metal(s) over the I/O pads, followed by an addition of solder or gold "bumps" to provide reflow or thermocompression bonding areas for copper beam-lead attachment. See TAB.

Buried Layer
A low-resistivity, diffused region placed under the collector of a bipolar transistor to reduce its series resistance, commonly employed with an epitaxial structure.

Burn-In
Applying voltage to a semiconductor device at an elevated temperature for a given period of time to cause devices with marginal reliability to fail, eliminating potential field failures.

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CAD
(Computer-Aided Design). A technique of using a computer to aid a person in the design of electrical circuits, integrated circuits, gate arrays, and other complex engineering designs in a reasonable timeframe.

Cantilever Loading
A mechanical support structure that allows process boats to be inserted and removed from the process chamber without touching the walls of the process chambers.

Capacitance (C)
The capability of storing electrical charge. Unit of measure is the Farad (F).

Capacitance - Voltage Plot or C-V Plot
(1) A measurement method used to characterize the dopant profile of a p-n junction.

(2) An evaluation technique used to measure the quality of a dielectric for fixed charge density (QF), trapped charge density (QB), and mobile charge density (QM). Depending on the methodology chosen, substrate characteristics can also be determined.

Carriers
Holes or electrons that are available in a semiconducting device for conduction of electric current.

Carrier Gas
An inert gas used to transport other elements to a process chamber or tube.

Cathode Sputtering
A method of depositing thin films, that employs a high-energy bombardment to release the source material.

Cause and Effect Diagram
A method of delineating all possible root causes of a problem using brainstorming.

CCD
(Charge Coupled Device). A device utilizing a technique in which information is stored and transported by means of packets of minute electrical charges.

Centerless Grinding
A special grinding process used to shape the grown boule (ingot) into the final diameter. This process is done prior to slicing the boule into the individual wafers.

CERDIP
(CERamic Dual-Inline Package). A package assembled with the leadframe sandwiched between two ceramic layers and sealed by firing a glass frit.

CERMET
A combination of ceramic and metal powders used for thin-film resistors (and thick-film).

CERPACK
(CERamic PACKage). A cerdip-like package with the leadframe extending out all four sides, typically in surface-mounting format. Characteristics similar to cerdip. Also known as cerquad, cerpac or cerpak.

Channel
The conducting layer between source and drain of an MOS transistor that is induced by the applied gate voltage.

Chemical Etching
The use of liquid chemicals to remove a particular material.

Chemical Mechanical Polishing
A process methodology that uses both chemical reactions and mechanical forces simultaneously to remove materials from a surface. This methodology is used for planarization in semiconductor manufacturing.

Chip
An integrated circuit or discrete device. Also called a die.

Chip Carrier
A square (or rectangular) IC package with I/O connections on four sides; connections may be leadless or leaded.

Chrome, Chromium (Cr)
A metal element.
(1) The metal is used as the opaque layer in a reticle and or mask.

(2) The metal is used as part of a die attach alloy or metal interconnect composition.

Circuit Layout
The physical arrangement of all the circuit elements on the surface of the device.

Cleanroom
An area specially constructed to control the air flow, temperature, and humidity in such a way that constant filtration keeps contamination below some predetermined level and temperature and humidity within predetermined limits.

Cleanroom Class
A government specification issued as FED-STD-209 that defined the number of particles of a given size and distribution per cubic volume of space for each Class.

CMOS
Complementary metal-oxide semiconductor. A logic family made by combining N-channel and P-channel MOS transistors.

Coefficient of Diffusion
The rate at which a diffusant will diffuse into bulk material at a given temperature; measured in cm2/sec.

Coherent Light
Having waves in phase and of one wavelength.

Collector
The region of a bipolar transistor that "collects" the emitted electrons and then passes them on through a conductor, completing the electrical circuit.

Collimated Light
Light in which the rays are parallel.

Collimated Sputtering
A grid between the target material and the wafer that causes the deposition of the material to travel perpendicular to the wafer surface.

Compound Semiconductor
A semiconductor usually formed by the compound of Group III and Group V elements such as GaAs, GaInP, etc.

Concentration (Dopant)
The level of dopant materials as compared to "pure" semiconductor materials within the structure. The net concentration establishes the characteristic conduction pattern and other characteristics of the material.

Conductor, Electrical
A material capable of carrying (conducting) electricity. Silver is the best electrical conductor. Copper, gold, and aluminum are also popular conductors. Aluminum is the conductor most commonly used in IC fabrication.

Contact Aligner
An optical system that uses contact printing (the mask touches the wafer) to expose a wafer.

Contact Printing
Exposure of a wafer by passing light through a mask that is in direct contact with the photoresist-coated wafer. Chrome working plates are most commonly used due to their longer life, but emulsion working plates can be used to reduce damage to the wafer.

Contacts
The regions of exposed silicon that are uncovered prior to the metallization process to provide electrical access to individual devices.

Contamination
A general term used to describe unwanted material or foreign matter that adversely affects the electrical characteristics of a semiconductor wafer.

Core Logic
Handles all of the communication and data traffic between the microprocessor and other components within the system.

Critical Angle
Angle of incidence for which the angle of refraction is 90 when light goes from one medium of high index of refraction into one of lower index.

Critical Dimensions (CD's)
The width or space of critical circuit elements in an IC.

Crossovers
Locations in integrated circuits where separate current paths cross one another. These are accomplished by using a low resistance diffused path (emitter diffusion) for one path and the metallization for the other. The two paths are insulated from one another by the SiO2.

Crystalography
The science and classification of crystals, particularly the semiconductor material employed to fabricate transistors and integrated circuits.

Crystal Orientation
The relationship of wafer surface to the crystal facets at which the crystal is sliced. Crystal orientation has a direct effect on device characteristics.

Cum (Cumulative) Yield
The output of several manufacturing process steps divided by the input or the yields of several consecutive steps multiplied together.

Current (I)
The flow of electrons. Usually measured in amperes (amp or A).

Curve Tracer
An electrical tester that displays a X & Y relationship on the face of a CRT.

CVD
(Chemical Vapor Deposition). A method of uniformly depositing films of insulators or conductors on a wafer to either isolate or connect circuit elements. Lithography defines a pattern of film that is to remain after an etch step.

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Darlington Amplifier
An amplifier in which the collectors are tied together, and the emitter of the first directs current to the base of the second.

Deep Ultraviolet or Deep UV
Refers to the electromagnetic spectrum where the wavelength of light is less than 300 nanometers.

Dehydration Bake
A heat cycle wafers receive prior to photolithography processing.

Depth-of-Focus
The focal length of a lense system to maintain a precise image size.

Depletion Device
A type of MOSFET which is "on" when no input signal is present.

Depletion Region
That area at a P-N junction which, when reverse biased, is swept clear of free charges.

Deposition
A heat or physical (sputtering) process whereby a thin film of material is deposited over the surface of a wafer.

Development
A chemical process that removes the photoresist from areas not defined by the mask in a lithographic procedure.

Develop Inspect or A.D.I.
The inspection a wafer receives after the photoresist development process.

Developer
The liquid solution used to resolve an image after exposure.

Diborane (B2H6)
A gaseous compound of boron and hydrogen used as P-type dopant.

Die
A single square or rectangular piece of semiconductor material into which a specific electrical circuit has been fabricated. Plural is dice. Also called a chip or device (IC or discrete).

Dielectric
A non-conductor of current, an insulator

Die Sort
See Wafer Sort.

Die Bonding
See Bonding, Die.

Differential Amplifier
An amplifier that amplifies the voltage difference between two input signals and has two inputs and two outputs.

Diffraction
Spreading or bending of a wave upon passing around an obstacle or through a narrow opening.

Diffusion
A high-temperature process by which selected chemicals (dopants) enter the crystalline structure of semiconductor materials to change the electrical characteristics at desired locations. This process takes place in a diffusion furnace.

Digital
A method of representing information in an electrical circuit by switching the current ON or OFF. Only two output voltages are possible, usually represented by "0" and "1."

Digital Circuit
A circuit that operates like a switch and can perform logical functions. Used in computers or similar logic-based equipment.

Diode
A two-terminal device that allows current to flow in one direction but not the other. A diode is present at the intersection (junction) of a P-type and an N-type semiconductor.

D.I. (Deionized) Water
Water that has been specially processed to remove all ionized impurities and filtered to remove particle contamination.

DIP
(Dual In-line Package). The most common type of IC package; circuit leads or pins extend symmetrically outward and downward from the long sides of the rectangular package body.

Direct Current
The flow of electrons only goes in one direction. Abbreviated DC.

Direct Step On Wafer (DSW)
See Stepping Aligner

Discrete Device
A semiconductor containing only one active element, such as a transistor or a diode.

DMOS
(Double-diffused MOS). Also called VMOS (differing from V-groove MOS), for its vertical flow of current through the substrate.

Donor
A dopant that can make a semiconductor N-type by donating extra "free" electrons to the conduction band. The free electrons are carriers of negative charge. See acceptor.

Dopant (also Diffusant)
Dopants are the materials used to change the electrical characteristics of a semiconductor crystal, making it N- or P-type.

Doping
The introduction of an dopant into a semiconductor to modify its electrical properties by creating a concentration of N or P carriers. Doping is normally accomplished through diffusion or ion implantation processes.

Drain
The working current terminal (at one end of the channel in a MOSFET) that is the drain for holes or free electrons exiting from the channel. Corresponds to collector of a bipolar transistor.

Driver
An element that is coupled to the output stage of a circuit in order to increase its power, current handling capability, or fanout; for example, a clock driver is used to supply the current necessary for a clock line.

Drive-In
The second part of a two-part diffusion. It is the part of the operation in which the diffusant deposited during predeposition is diffused further into the wafer to achieve the desired impurity profile.

Dry Etch
The process that uses RF energy and gas phase chemicals to remove a specific layer during semiconductor processing.

Dry Oxide
The thermal oxidation of silicon using dry oxygen gas.

Dynamic Ram (DRAM)
A type of semiconductor memory in which the presence or absence of a capacitive charge represents the state (0 or 1) of a binary storage element. The charge must be periodically refreshed.

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E-Beam
Electron beam. Refers to an electron-beam evaporator or exposure system.

ECL
(Emitter Coupled Logic). A form of current-mode logic in which the output is available from an emitter-follower output stage.

EEPROM or E2PROM
(Electrically-erasable PROM.) Similar to ROM, but with the capability of selective erasure and programming through special electrical stimulus.

Electron
An elementary, negatively charged atomic particle.

E-Beam Evaporation
A deposition process that concentrates an electron beam upon a material to be evaporated, raising the material to its vaporization point. The material is deposited on the surface of the wafers as it cools (freezes).

E-beam Exposure System
An electronic imaging system that controls the exposure of a photo-imageable material by turning an electron-beam on and off, thus writing the exposure pattern of a database tape into the photoresist.

Edge Die
The two or three rows of dice along the outer circumference of the wafer.

Electromagnetic Spectrum
Spectrum of all electromagnetic radiations, both visible and invisible, that do not require a medium in which to move.

Electromigration
The result of the movement of electrons in a conductor when the electric field is raised to a very high level and the operating temperature is high. This results in a physical displacement of conductor atoms. If the conditions are severe at high current densities, this eventually leads to an open conductor and circuit failure.

Ellipsometer
An optical measurement instrument that processes the optical constants of light and outputs the refractive index and thickness of films.

Emitter
The region of a bipolar transistor that serves as a source or input end for carriers. N-type for NPN, P-type for PNP.

Emitter Diffusion
The diffusion during which the emitters of bipolar transistors are formed.

Emulsion Mask
A transparent mask plate on which the opaque region is a suspension of a salt of silver in gelatin or collodian.

Enhancement Device
A type of MOSFET that requires a control signal input to turn on the device. The device is "off" when no input signal is present.

Epi
Short for epitaxy, the controlled growth of a layer of crystalline semiconductor material on a suitable substrate.

Epitaxial Layer
A grown crystal layer (usually doped) having the same crystallographic orientation as the substrate (wafer). Also called "epi."

Epoxy
A family of thermosetting resins used in the packaging of semiconductor devices. Epoxies form a mechanical bond to many metal surfaces. Also used to attach dice to substrates or leadframes.

EPROM
(Erasable Programmable Read-Only Memory). Similar to ROM, but enables the user to erase stored information. Normally refers to a memory device whose contents may be erased by exposure to ultraviolet light shined through a window in the ceramic package.

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

Evaporation
A vacuum process, usually at less than 10^-6 Torr (mm of Hg), where metal(s) are vaporized through thermal agitation, then recrystallized on cooler surfaces, generally the semiconductor wafers.

Excimer Laser
A coherent light source based on krypton fluoride, krypton chloride, argon fluoride, and fluoride species.

Exposure
Subjecting a sensitive chemical or material to light or other radiant energy.

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Fabless
A semiconductor company that does not have their own wafer manufacturing facility, but subcontracts the wafer manufacturing.

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

Failure Analysis
An orderly procedure for determining the reason that a device has failed. The results are frequently useful for enhancing the reliability of subsequent products.

Failure in Time
One failure in 10^9 device hours.

Failure Rate
A rate of failure per unit time, for example, 3 failures per 164 hours or 1 failure per day, etc. Semiconductors are usually measured in failures per 1000 hours.

Feature Size
See "Minimum Geometry".

Femto
A prefix meaning one quadrillionth (x10^-15). Symbol is f.

Ferroelectric RAM
DRAM's that have the capacitor dielectric made from ferroelectric materials.

FET
(Field Effect Transistor). A solid-state device in which current is controlled between source and drain terminals by voltage applied to a gate terminal, which is insulated from the semiconductor substrate.

Field Oxide
A thick layer of dielectric, generally silicon dioxide, that covers the inactive portion of the semiconductor surface.

Final Test
The electrical evaluation of the packaged device.

Flat Band Voltage
The voltage at which the net charge in the semiconductor is zero.

Flat Pack
A ceramic surface-mounted hermetic package. Very popular for military applications because of its small size, but characterized by lead and package seal fragility, poor structural strength, excessive gold, and loose particle problems.

Flat Zone
The region in a process tub or chamber where the temperature is controlled to some specification tolerance.

Flip-Chip
An IC designed for face-down mounting, attached by controlled-collapse solder pillars on I/O (bonding) pads of the device.

Flip-Flop
An electrical circuit having two stable states: on and off. A basic logic circuit component.

Four-Point Probe
An electrical evaluation instrument that measures sheet resistance. Contains four precisely spaced probes that contact the semiconductor surface and measure the dopants within the semiconductor wafer.

FPLA
(Field Programmable Logic Array). A PLA that can be programmed by the user.

Frequency
The number of times per second an alternating current goes through a complete cycle. Formerly expressed in cycles per second. Now expressed in Hertz (Hz).

Furnace
A piece of process equipment containing heating elements connected to precision controller. The controller allows a zone of constant temperature to be maintained to a tight tolerance.

Fuse
An electrical circuit element that allows only some maximum level of current flow before it becomes an open circuit.

Fuseable Link
A circuit element used in memory circuits as a programmable connection.

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GaAs
(Gallium Arsenide). A compound semiconductor material in which active devices are fabricated. GaAs has a higher carrier mobility than silicon, thus it has the capability of producing higher speed devices.

GaAs FET
A discrete field effect transistor used to amplify higher frequency radio signals.

Gate
(a) The basic digital logic element - where the binary value of the output depends on the values of the inputs.

(b) The primary control terminal of a field effect transistor.

Gate Array
An IC consisting of a regular arrangement of gates that are interconnected to provide custom functions. Sometimes called an uncommitted logic array (ULA).

Gate Equivalent
The basic unit of measure for digital circuit complexity, based on the number of individual logic gates that would have to be interconnected to perform the same circuit function.

Gate Oxide
The thin layer of thermal oxide separating the gate electrode (terminal) from the semiconductor substrate.

Germanium (Ge)
A brittle, grayish-white metallic element having semiconductor properties. Widely used in crystal diodes and early transistors.

Gettering
To collect and neutralize unwanted elements.

Giga
Prefix meaning one billion (x10^9). Symbol is G.

Glassivation
Passivation using silicon dioxide (glass).

G-Line
The 436nm wavelength of the electromagnetic spectrum. It is in the UV portion of the spectrum.

Graphic ASSP's
Are tailored to specific monitor requirements, handle colors and because they are dedicated chips, they do so at accelerated speeds.

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Hard Surface
A photoplate coated with a relatively hard, non-emulsion coating that can be selectively etched to produce a photomask. Popular hard surface materials are chromium, chromium oxide, and iron oxide.

Hardware
The physical components of a computer or an electronic system - as opposed to software, which is the term used to describe the programs and instructions for a computer.

Heat Sink
An assembly that serves to dissipate, carry away, or radiate into the surrounding atmosphere heat that is generated by an active electronic device.

HEPA Filter
(High Efficiency Particulate Air) Filter. A specially constructed filter membrane that allows a high volume of air flow and stops small particles of some pre-determined size from passing through. In a semiconductor cleanroom the maximum particle size will range from 0.5m down to less than 0.1m.

High-Pressure Oxidation
A special pressure vessel contained inside a resistance heated furnace. This pressure vessel allows thermal oxidation to be performed at elevated pressure levels of 5 to 25 atmospheres.

Hillock
The displacement of a thin-film material that occurs when heated and cooled. Hillocks of aluminum are sometimes found in the aluminum interconnect metal on semiconductor devices.

Histogram
A bar graph used to display large amounts of variable data for analysis.

Hexamethyldisilizane (HMDS)
A chemical primer used to promote improved adhesion between the photoresist layer and the underlying surface.

H-Line
The 405 nm wavelength.

HMOS
(High-performance MOS) A scaled, high-performance NMOS structure.

Hole
The absence of a valence electron in a semiconductor crystal. The movement of a hole is equivalent to the movement of a positive charge.

Hybrid Circuit
A microelectronic device consisting of both film circuits and semiconductor elements.

Hydrofluoric Acid (HF)
A strong acid used to remove silicon dioxide. Generally it is mixed with ammonium fluoride for better etch-rate control.

Hydrogen (H2)
A common gas used in semiconductor processing. One must be cautious of the explosive nature of hydrogen.

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Image
The defined pattern on a surface.

Incoherent Light
Lacking orderly continuity.

Information ASSP's
Manage input/output network information between discrete components in the network.

Integrated Circuit (IC)
A semiconductor die containing multiple elements that act together to form the complete device circuit.

I2L
(Integrated Injection Logic) A bipolar structure characterized by an integrated PNP load device and inverted operation of an NPN logic transistor.

Illumination
Rate at which area of a surface receives light.

I-Line
The 365nm wavelength.

Impurity
Any foreign or undesired material that gets incorporated into the semiconductor material or layers above the silicon surface.

Index of Refraction
Ratio of the speed of light in a vacuum to the speed of light in a particular substance; ratio of the sine of the angle of incidence to the sine of the angle of refraction.

Ingot
A term used to describe the single-crystal silicon mass after the crystal growing process. Also called boule.

Interconnect
A conductive connection between two or more circuit elements. The conductors among elements (transistors, resistors, etc.) on an integrated circuit or between components on a printed circuit board.

Insulator
A material that is a poor conductor of electricity - used to separate conductors from one another or to protect personnel from electricity.

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

Ion Beam Milling
A process of physically removing unwanted (unprotected) material from a semiconductor surface by ion bombardment.

Ion Implantation
A means for adding dopants to a semiconductor material. Charged atoms (ions) are accelerated in an electric field into the semiconductor material. It is especially useful for thin doped areas. This process is much more precise than the diffusion method of doping.

Isolation Diffusion
A method of achieving isolation by diffusing in such a manner that P-N junctions surround the areas to be isolated from one another.

Isotropic
In a subtractive process (etching), the material is removed in all directions simultaneously, frequently at the same rate vertically and horizontally.

ISL
Integrated Schottky Logic.

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JFET
(Junction Field Effect Transistor). A solid-state device in which current is controlled between source and drain regions by voltage applied to a conducting or junction gate terminal.

Junction (P-N)
The line of demarcation where the number of P- and N-type carriers are exactly equal with a surplus of P-type on one side and N- type on the other.

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Kilo
A prefix meaning a multiple of 1000 (x10^3). Symbol is K.

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Latch Up
(1) In an electrical circuit this refers to when the circuit is conducting and hold this state.

(2) In CMOS this refers to the parasitic conduction that occurs when the parasitic n-p-n and p-n-p transistors get turned on.

Laterial PNP Transistor
An integrated transistor that is made in such a way that the transistor action is laterally across the surface of the diffusions rather than vertically through the N and P diffusions.

Leadframe
A stamped or etched metal frame that provides external electrical connections for a packaged electrical device.

LCC
(Leadless Chip Carrier). Usually made of ceramic material.

LED
(Light-Emitting Diode). A compound semiconductor device that emits light whenever current passes through it.

Light
Electromagnetic radiation that may or may not be visible to the human eye.

Line Width
Width of an opaque line. Usually refers to a dimension on a mask or a feature on an IC.

Linear Device
An amplifying-type (or analog) device, as opposed to digital device.

Linear Circuit
A circuit whose output is an amplified version of its input or whose output is a predetermined variation of its input.

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. "Microlithography" refers to the process as applied to images with features in the submicron range.

LOCOS
LOCal Oxidation of Silicon.

Low-Pressure Chemical Vapor Deposition (LPCVD)
Chemical vapor deposition process performed at reduced (less than atmospheric) pressure.

LSI
(Large-Scale Integration). ICs containing 1,000 or more transistors, but less than 100,000.

LSTTL
(Low-power Schottky TTL). The power dissipation of LSTTL is typically one-fifth that of conventional TTL.

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Magnetron Reactive Ion Etch (MRIE)
The use of magnet to shape the ion field of etchant molecules in a reactive ion etch system.

Magnification
Ratio of size of optical image to size of the object.

Majority Carrier
The mobile charge that predominates in a semiconductor material. Electrons in N-type material and holes in P-type material.

Mask
A transparent (glass or quartz) plate covered with an array of patterns used in making integrated circuits. Each pattern consists of opaque areas that prevent light passage. The mask is used to expose photoresist that defines areas to be later etched on a wafer. Masks may use emulsion, chrome, iron oxide, silicon, or other material to produce the opaque areas.

Mask Trimmer
A device that uses bursts of laser energy to vaporize and remove unwanted opaque areas or spots on a photomask or reticle.

Mass Flow Controller (MFC)
A gauge consisting of a mass flow meter, an electronic controller and a valve that can control the rate of flow of a gas.

Mass Storage ASSP's
Manage information between storage components in the system and the microprocessor.

Master Plate
Original photomask generated by a step-and-repeat camera or e-beam system, used to print submasters or working plates.

MCBF
(Mean Cycles Between Failures) is obtained by dividing Mean Time Between Failures by the length of time required to complete one operating cycle.

Mega
A prefix meaning a multiple of one million (x10^6). Symbol M.

Memory
A general term for computer hardware that holds information in electrical or magnetic form.

MESFET
(Metal Schottky FET). A field effect transistor whose gate structure consists of a metallic Schottky barrier.

Metal-Gate MOS
MOS devices with a metal layer deposited to form the gate elements.

Metal Mask
The photomask used to define the metal interconnects in an IC.

Metallization
Metallization is the process of depositing a thin film of metal and patterning it to form the desired interconnection arrangement.

Metrology
The science of precise weight and measurement.

Micro
A prefix meaning one-millionth (x10^-6). Symbol is

Microcomputer
A microprocessor complete with stored program memory (ROM), random-access memory (RAM), and input/output (I/O) logic. Microcomputers are capable of performing useful work without additional supporting logic. If all functions are on the same chip, this is sometimes called a microcontroller.

Micrometer
One-millionth (10^-6) of a meter. About 40 millionths of an inch. Synonymous with micron. Symbol is m.

Micron
A term used for micrometer.

Microprocessor
The basic arithmetic logic of a computer. Also called MPU for microprocessor unit.

Mil
One-thousandth of an inch (10^-3 inch). Equal to 25.4 microns.

Miller Indices
A set of three integers used to define a set of parallel planes. The integers are derived from the coordinate system of the basic vectors.

Milli
A prefix meaning one-thousandth (x10^-3). Symbol is m.

Minority Carrier
The non-predominant mobile charge carrier in a semiconductor. Electrons in P-type material and holes in N-type material.

Minimum Geometry
The smallest line width or spacing between lines or features on a semiconductor die. May be defined "as drawn" or "as printed."

MMIC
(Monolithic Microwave IC). An analog IC with on-chip inductors and capacitors designed to work at microwave frequencies.

MNOS
(Metal Nitride Oxide Semiconductor). The dielectric between metal and semiconductor is fabricated from silicon nitride. This technology is commonly used to make EEPROMs.

Mobility (Hole or Electron)
The rate with which a carrier (majority or minority) moves within a material under the influence of an electric field.

Molecule
An aggregate of two or more atoms of a substance that exists as a unit.

Monochromatic Light
(1) A single wavelength of light energy.

(2) Light of only one color.

Monolithic Device
A device whose circuitry is completely contained on a single die or chip.

MOS
(Metal Oxide Semiconductor). Refers to field effect transistors (FETs) in which current flows through a channel of semiconductor material that is controlled by the electric field under a gate structure.

MOSFET
A type of field effect transistor. See MOS.

PU
(Microprocessor Unit.) Sometimes used synonymously with the word microprocessor.

MSI
(Medium-Scale Integration). A term generally applied to integrated circuit chips containing 30 or more transistors, but less than 1,000.

MTBF
(Mean Time Between Failures) is the reciprocal of the sum of the failure rates of every component in a system.

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NAND Gate
(Not-AND gate). An AND gate followed by an inverter. The output of the AND gate is inverted to the opposite value.

Nano
A prefix meaning one-billionth (x10^-9). Symbol is n.

Negative Resist
A photoresist that remains in areas that are exposed by light shined through the clear regions of a mask. A negative image of the mask remains following the development procedure.

Nitric Acid (HNO3)
A strong acid used in semiconductor processing.

Nitrogen (N2)
An inert gas used as a carrier or purge gas in semiconductor processing.

NMOS
Also called N-channel MOS. A type of MOSFET using electrons to conduct current in the semiconductor channel. The channel has a predominantly negative charge during conduction. The source and drain are N-type.

Noise Immunity
A measure of the insensitivity of a logic circuit to triggering by or reaction to spurious or undesirable electrical signals or noise, largely determined by the signal swing of the logic.

Non Volatile Memory
A memory device that maintains the memory states after power is removed.

NOR Gate
(Not-OR). An OR gate followed by an inverter. The output of the OR gate is inverted to the opposite value.

NOT Gate
The output is just the opposite from the single input.

Novolac Resin
A phenolic polymer; the major component of a positive tone photoresist for near UV exposure.

N-type Semiconductor
A semiconductor crystal containing a small amount of "dopant" atoms that have one more valence electron that the other atoms in the crystal. These extra negative electrons can find no unoccupied bonds to bind them, so they are free to wander and constitute electric current. Common N-type dopants for silicon are phosphorus and arsenic.

Numerical Aperture
A design function of a lense system that relates the refractive index of the lense material and the cone angle of the lense such that the NA is equal to the refractive index of the lense times the sine of the cone angle of the lense. (N.A. = n siny)

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OP Amp
(Operational amplifier). A general-purpose IC used as a basic building block for implementation of linear functions.

Opaquing
The application of minute droplets of opaque ink to fill pinholes and correct geometric areas of mask or reticles.

Optical Center
Point in a lens through which light rays pass without refraction.

Optical Density
Property of an optical material that determines the speed with which light rays travel through it.

Optoelectronics
Solid state devices capable of emitting a specific wavelength of energy, sensing a specific wavelength of energy or interacting together in a common package to perform an electronic function.

OR Gate
The output is yes if at least one input is yes.

Oxidation
The chemical process of joining oxygen with another element. In semiconductors, oxidation means the joining of oxygen and silicon to form silicon dioxide (SiO2).

Oxide
Usually refers to silicon dioxide (SiO2) in semiconductor terminology.

Oxide Etching
The removal of silicon dioxide.

Oxygen (O)
An element that is used in the formation of silicon dioxide (SiO2).

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Package
The protective container for an electronic component - with terminals to provide electrical access to the components inside.

Parameter
A numerical measurement describing some characteristic of a population.

Parasitic
A parasitic is an undesirable stray capacitance, inductive coupling, or resistance leakage, as well as undesired transistor actions. The first and last are most serious in monolithic integrated circuits.

Pareto Diagram
A special form of bar graph used to expose the most important elements in a category.

Parfocal
The field of view essentially remains in focus when switching between objective lens on a microscope.

Partial Coherence
A ratio of the numerical aperture of the condenser lens divided by the numerical aperture of the objective lens.

Parts Per Million
The presence of one part in a million parts.

Passivation
A layer of material put over a wafer to stabilize and protect the surface. Silicon dioxide or silicon nitride are often used for IC passivation.

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

Patterning
The transferring of an image from a reticle or mask to the photo resist.

Pattern Generator
A system that automatically generates a reticle from the coded images defined by a CAD system.

Pellicle
A thin, transparent membrane that seals off the mask or reticle surface from airborne contamination.

Penumbra
Portion of a shadow in which only part of all the light rays from a given source are cut off by an intervening body.

PG Tape
The magnetic tape output of a CAD system that is used to drive a pattern generator.

Phosphine (PH3)
A compound of phosphorus and hydrogen used in semiconductor processing. The material is very toxic. It is a N-type dopant.

Phosphorus (P)
The N-type dopant commonly used for the buried layer contact and emitter diffusions in standard bipolar IC technology, and the source/drain regions in NMOS.

Phosphorus Oxychloride (POCl3)
A chlorinated phosphorus compound used as an n-type dopant.

Photo Active Compound (PAC)
The sensitor chemicals in positive photoresist to cause the resist to chemically respond to the UV energy.

Photolithography
Lithographic techniques involved light as the pattern transfer medium. See Lithography.

Photoplate
The term used for a mask before images have been formed on it.

Photomask
See Mask.

Photoresist
A light-sensitive liquid that is spread as a uniform thin film on a wafer or substrate. After baking, exposure of specific patterns is performed using a mask. Material remaining after development resists subsequent etch or implant operations.

Pico
A prefix meaning a trillionth or one-millionth of one-millionth (x10^-12). Symbol is p.

Pin Array
(Or pin-grid array or area array). A package with pins distributed over much or all of the bottom surface of the package.

Pinhole
A small undesired hole in an oxide, opaque region of a mask or reticle, or in a photoresist layer.

PLA
(Programmable Logic Array). A general-purpose logic circuit containing an array of logic gates that can be connected (programmed) to perform various functions.

Planar
Existing essentially in a single plane; a process in which all PN junctions intersect the top surface of the semiconductor material, such that these intersections are permanently protected by the masking oxide, and all contacts to the device can be made to the top surface.

Planar Process
The planar process of forming integrated circuit and semiconductor components is based upon the use of a single surface for referencing each successive operation. The planar process depends upon the repeated use of silicon dioxide (SiO2) on the surface to control the location of impurities.

Plasma
An electrically conductive gas composed of ionized particles which are used to etch unwanted material through a chemical or physical bombardment process. Plasma etching takes place in a reactor, which may be of the barrel type or the planar type.

Plasma Enhanced Chemical Vapor Deposition (PECVD)
Low Pressure Chemical Vapor Deposition using RF energy.

Plasma Etching
The utilization of RF energy added to a chemical in gas form producing a glow discharge. This glow discharge contains chemically reactive species, (atoms, radicals, ions) which react chemically with the material to be removed, whose by-products are volatile.

PLCC
(Plastic Leaded Chip Carrier). A leaded quad package - a replacement for the plastic DIP in surface mount applications.

PMOS
(P-channel MOS). A type of MOSFET using holes to conduct current in the semiconductor channel. The channel has a predominantly positive charge during conduction.

Polychromatic Light
Light consisting of several colors, or wavelengths.

Polycide
Doped polysilicon that has a refractory metal added to the top surface of the polysilicon.

Polysilicon
Polycrystalline silicon. Sometimes call "poly." The form of silicon made of many small randomly-oriented crystals. Doped poly is a conductor of electricity and is often used as an alternative to metal in interconnecting devices on integrated circuits.

Population
The entire collection of elements to be studied.

Positive Resist
Photoresist that is removed in areas that were not protected from exposure by the opaque regions of a mask - while remaining in regions that were protected by the mask. The positive image of the mask remains following the development.

Predeposition
The first part of a two-part diffusion. In this part, a high concentration is diffused shallowly into the surface. This acts as a source for the second or drive-in portion of the process.

Preforms, Solder
Formed pieces of solder material for closing microcircuit packages. Additionally used in some applications to attach chip to package.

Printed Circuit Board (PCB)
A substrate on which a predetermined pattern or printed wiring and printed elements has been formed. Also called a printed wiring board (PWB).

Probing
A term used to describe testing of individual IC dice by using very fine probes to temporarily connect each to a test computer, thus verifying proper operation. A bad die will usually be marked with a spot of ink.

Process Control Charts
A graphical method of determining when special cause variation exists in a manufacturing process.

Process Capability
Quantification of the natural variation that exists in a manufacturing process.

Process Capability Index
A figure of merit that indicates the ability of a process to perform to a specification.

PROM
(Programmable Read-Only Memory). A read-only memory that can be programmed after manufacture by external equipment. Typically PROMs utilize fusible links that may be burned open to produce a logic bit in a specific location.

Propagation Delay
The propagation delay of a circuit is the finite period of time (delay) measured from the instant when the input signal(s) is applied until the output has reached its final value.

Proximity Aligner
An optical system that uses proximity printing to expose a wafer.

Proximity Printing
Exposure of a wafer by passing light through a mask that is very close to, but not in contact with, the photoresist-coated wafer. Collimated light is required to ensure minimum image resolution.

P-type Semiconductor
A semiconductor crystal containing a small amount of "dopant" atoms that have one less outer electron than the other atoms. Each "dopant" atom causes one unoccupied spot, called a "hole," among the electrons that are bound in their orbits. The holes are positively charged and in effect move, constituting an electric current. Boron is a commonly used P-type dopant for silicon.

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Quadruple Illumination
Illumination source for the reticle, produced by four light sources symmetrically placed about the center of the optical axis of the stepper lens.

Qualification
The technique of evaluating samples to qualify or approve a production lot from which they are produced.

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RAM
(Random-Access Memory). Stores digital information temporarily and can be changed as required. It constitutes the basic (read/write) storage element in a computer.

RCA Clean
A special wet chemical cleaning process using a combination of water, peroxide, and ammonium hydroxide followed by water, hydrogen peroxide, and hydrochloric acid.

Rapid Thermal Processing (RTP)
The use of radiant light energy to heat silicon wafers very rapidly to elevated temperatures.

Reactor
A term used to describe a piece of semiconductor process equipment used for depositing various layers.

Refractory Metal
A metal that has high temperature stability. Generally refers to those metals in the Periodic Groups of IVA, VA, and VIA.

Registration Overlay
The accuracy of position of all patterns with respect to previous patterns that form other layers of a semiconductor wafer.

Rise Time
A measure of the time required for the output voltage to change from a low voltage level ("0") to a high voltage level ("1") once a level change has been started.

Resistance (R)
The difficulty in moving electrical current through a conductor to which voltage is applied. Expressed in ohms.

Resistivity (r)
A physical property of a material to resist or oppose the movement of charge through the material. Expressed in ohm-cm.

Resolution
The smallest image that can be clearly discerned.

Reticle
In semiconductor parlance, a glass or quartz substrate with a 10X image of a single IC. The 10X reticle is produced by a pattern generator. The 10X pattern may be optically reduced and stepped onto a master plate, or used directly on a stepping aligner system (commonly referred to as a stepper).

Rinse
The use of D.I. water to neutralize, clean, and remove another liquid.

ROM
(Read-Only Memory). Permanently stores information repeatedly used-such as tables of data, characters of electronic displays, etc. Unlike RAM, ROM cannot be altered.

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Salicide
Self-aligned silicide gate.

Sample
A subset of a population.

Scaling
A technique of reducing the size of an existing integrated circuit die by selective shrinking of the X and/or Y dimensions.

Scanning Electron Microscope (SEM)
A microscope that uses an electron beam to scan a specimen under vacuum, providing a very high magnification of the surface. This magnification is generally in the range of 10X - 100,000X.

Scanning Projection Aligner
An optical system that uses a slit of light to transfer the mask image to the photoresist-coated wafer. The slit of light is scanned across the mask and is projected onto the wafer.

Schottky TTL
A form of TTL logic in which Schottky diodes are used to clamp the transistors out of saturation, effectively eliminating the storage of charge within the transistor - allowing increased switching speeds.

Scribe Line or Saw Lane
The separation between adjacent die on the wafer. This path is used as the cutting area in sawing a wafer into the individual die.

Selective Etching
Etching that is done so that certain material is dissolved, but other materials are not affected by the etchant.

Semiconductor
A material with properties of both a conductor and an insulator. Common semiconductors include silicon and germanium.

Sheet Resistance
Sheet resistance is a characteristic of material that is formed in such a way so that its resistivity is not a function of its cross-sectional structure. Sheet resistance is expressed as RS in terms of ohms per square, where the square refers to surface area but has no absolute dimensions.

Side-brazed Ceramic Package
A multilayer ceramic dual in-line package (DIP) with external leads brazed on the sides of the package.

Silane (SiH4)
Pyrophoric (spontaneously combusts in air) gas commonly used in CVD processes.

Silicon (Si)
The basic element used in most semiconductor devices; i.e.; diodes, transistors, and integrated circuits.

Silicon Dioxide (SiO2)
The compound of silicon and oxygen used for insulation (isolation), passivation, or a masking layer in semiconductors.

Silicon Nitride (Si3N4)
The compound of silicon and nitrogen used as a masking layer during processing and as a final passivation layer at the end of the process sequence.

Silicon-Gate MOS
MOS devices with a polycrystalline silicon layer deposited to form the gate elements.

Silicides
The reaction of a metal with silicon, forming a metal-silicon compound, i.e., PtSi (platinum silicide).

Single-Crystal
A piece of material having a continuous, regular crystalline lattice structure and having no internal grain boundaries.

SIP
(Single In-line Package) with a single row of pins (in picket-fence style). Package is usually mounted in the vertical plane.

Slice
Another term for wafer.

Soft Bake
A heat treatment used after the photoresist is applied to the silicon wafer to remove the solvents from the layer.

Software
The programs and instructions for a computer.

SO/SOIC
(Small Outline, Small Outline IC). A small plastic dual in-line package, usually with "gull wing" feet, designed for surface mounting. Most versions have lead spacing compatible with that of PLCC packages. Another version, SOT (Small Outline Transistor) has been popular in hybrid use for several years.

SOI
(Silicon-On-Insulator). Similar to SOS, but with oxide or another insulting film isolating individual transistors.

SOJ
(Small Outline, J bend). An SOIC package with j-bend leads.

Solid-State
Refers to electronic devices, like transistors, that conduct and control the movement of electrons in solid materials (instead of in a vacuum).

SOS
(Silicon-On-Sapphire). A fast MOS technology in which silicon is epitaxially grown on a sapphire wafer, and etched away between transistors. Each device is thus isolated by air or oxide from other devices.

Source
The working-current terminal of an FET that is a source for holes (P-channel) or free electrons (N-channel) flowing in the channel. Corresponds to emitter of bipolar transistors.

Spider Bonding
A method of connecting an integrated circuit die to its package leads. A leadframe is placed over the chip and all connections are made by just one operation of a bonding machine. Tape automated bonding (TAB) uses this approach to interconnection.

Spin or Spinning
The process used to apply the photoresist to the wafer surface.

Spreading Resistance
An evaluation technique used to measure the dopant profile of a p-n junction.

Sputtering
A method of depositing a film of material on an IC wafer. A target of the desired material is bombarded with excited ions that knock atoms from the target, which are then deposited on the wafer.

SSI
(Small-Scale Integration). ICs containing fewer than 30 transistors.

Standard Cells
Predefined logic elements that may be selected and arranged to create a custom IC more easily than through original (custom) design.

Standing Wave
Resultant of two superimposed waves of the same frequency traveling in opposite directions.

Static RAM (SRAM)
A type of semiconductor memory in which a pair of flip-flops are cross-coupled to hold a binary state as long as power is applied.

Statistic
A numerical measurement describing some characteristic of a sample.

Steam Oxide
The use of high-temperature water vapor to grow silicon dioxide. The source of water vapor can be from D.I. water or the pyrogenic reaction of hydrogen (H2) and oxygen(O2).

Step Coverage
The thickness of a thin film over topological changes relative to the thickness on the top surface.

Step-And-Repeat Camera
An optical system that reduces an enlarged reticle image to 1X on a master plate. After each exposure, the master plate is stepped to a new position and the exposure process is repeated.

Stepping Aligner
An optical system that projects (usually 2X, 2.5X, 5X or 10X) reticle images on a portion of the photoresist-coated wafer. After exposure, the wafer is stepped to a new position and the exposure process is repeated. Also refer to as stepper.

Stripping
The process of completely removing a coating such as photoresist.

Sub-Atmospheric Chemical Vapor Deposition (SACVD)
see LPCVD.

Subcollector
See Buried Layer

Submicron
Dimensions smaller than one micron.

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

Sulfuric Acid (H2SO4)
A strong oxidizing acid used to clean silicon wafers and remove photoresist.

Susceptor
A plate on which semiconductor wafers are heated during thermal processes such as epitaxy and chemical vapor deposition (CVD).

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TAB
(Tape Automated Bonding). A process utilizing metal conductors on beam tape, which are mass bonded to the IC die in a single operation.

Target
The source material for a sputtering process.

TCE (Trichloroethylene)
A solvent used for cleaning parts.

Thermal Compression Bonding
A method of wire bonding that does not use an intermediary metal or melting, but rather the plastic flow of materials resulting from the combination of heat and pressure. Also called thermocompression bonding.

Thermal Diffusion
See Diffusion

Thick-Film Process
A hybrid microelectronic process where conductors, insulators and passive components are screened from special pastes onto a substrate. This process is less expensive than the thin-film process, which uses depositions and photolithography techniques to define conductors, etc.

Thin-Film Process
The use of deposited films of conductive or insulating material, which may be patterned to form electronic components and conductors on a substrate, or used as insulation material between successive layers of components.

III-V Compound
Refers to semiconductors formed by combinations of materials in groups III and V of the periodic table of elements. Commonly refers to compounds of gallium, such as GaAs, GaInP, etc.

Threshold
The input voltage at which the output logic level changes state.

TO Package
(Transistor Outline) Standard mechanical packages used primarily for discrete transistors and low pin-count ICs.

Torr
The pressure exerted by 1mm of mercury. Atmospheric pressure is equal to 760mm of mercury.

Transistor
An active semiconductor device with three electrodes that may be either an amplifier or a switch.

Truth Table
All the combinations of possible states of the inputs and outputs of a circuit. It tabulates what will happen at the output for a given input combination.

TSOP
(Thin Small Outline Package). A thin SOIC or SOJ package.

TTL (or T2L)
(Transistor-Transistor Logic). A bipolar technology where a transistor output is connected directly (rather than through a resistor or diode) to a transistor input of the next stage.

Tube
The quartz tube inserted into the furnace that becomes the process chamber for diffusion and oxidation.

Turn-On Time
The time required for an output to turn on (sink current, to ground output, to go to 0 volt). It is the propagation time of an appropriate input signal to cause the output to go to 0 volt.

Turn-Off Time
Same as Turn-On Time except the output stops sinking, current goes off, and/or goes to a high voltage level (logic "1").

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ULSI
(Ultra Large Scale Integration). ICs containing 10 million or more transistors.

Ultrasonic Bonding
A wire bonding technique that utilizes ultrasonic energy and pressure to form the bond, without heat.

Umbra
Portion of shadow from which direct light from a given source is completely cut off by an intervening body.

Undercut
The lateral etching that occurs as the etching proceeds vertically.

Unipolar
Refers to FET devices where current passes only through one type of semiconductor material (P or N) as it flows from input to output.

UV
Ultraviolet - that portion of the electromagnetic spectrum with wavelengths between 290 nm and 480 nm.

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Vapor Plating
A vacuum process, usually at less than 10^-6 Torr (mm of Hg), where metal(s) are vaporized through thermal agitation, then recrystallized on cooler surfaces, generally the material to be coated. Also referred to as evaporation.

Vapor Priming
The process for coating the wafer surface with HMDS.

Variation
Change of a quantity in a physical event.

Via
A path filled with conducting material between circuit layers.

VLSI
(Very Large Scale Integration.) ICs that contain 100,000 or more transistors, but less than 10 million.

Volatile Memory
Memory devices that lose the stored states when power is removed.

Voltage
Electron potential in an electrical wire or circuit. Usually expressed in volts (V).

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Wafer
A thin disk of semiconductor material (usually silicon) on which many separate chips can be fabricated.

Wafer Fabrication
See Fabrication

Wafer Sort
The electrical testing of each die on the wafer while still in wafer form.

Wafer Flat
A region ground into the boule (ingot) to identify crystal orientation, dopant type and mask/reticle location reference.

Wavelength
Distance between two successive points of a wave that vibrate in the same phase.

Wedge Bonding
See Bonding, Wedge

Welding
Joining of two or more pieces of metal by fusing them together.

Working Plates
Masks printed from master plates that are used for production exposure of wafers. As these plates are subject to wear, they must be replaced periodically.

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X-ray
Radiations of short wavelengths between ultraviolet and gamma rays in the electromagnetic spectrum.

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Yellow Room
The room in which wafers coated with photoresist are exposed to ultraviolet light in an aligner. Fluorescent lights in the room have yellow filter tubes around them to block unwanted ultraviolet light from that source.

Yield
Yield is the ratio of the number of acceptable units to the maximum number possible.

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ZIF Socket
(Zero-Insertion Force socket.) A socket in which package leads are readily accepted by the socket, then firmly connected through cam action.

 

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