ACRONYMS and Vocabulary used and understood by the industry-at-large. This is a working list that was started in 1964. Please send in your old words & acronyms with definitions to aid researchers in their quest for understanding.

A/D Converter or ADC Analog-to-digital converter. A device to convert variable or analog signals to digital representation Access Time The time interval between the instant that data is called from or delivered to a storage device (memory) and the instant that requested retrieval or storage is complete Algorithm A prescribed set of well defined rules for the solution of a problem. Algorithms are implemented on a computer by a stored sequence of instructions. Alignment The arranging of the mask and wafer in correct positions, one with respect to the other. Special alignment patterns are normally part of the mask. Analog Indicates continuous, non-digital representation of phenomena. An analog voltage, for example, may take any value. 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 or BiPolar refers to transistors formed with two (N- and P- type) semiconductor types. (N=negative; P=positive) Bit A binary digit. A bit is the smallest unit of storage in a digital computer and is used to represent one of two digits in the binary number system. Buried Layer A low-resistivity diffused region placed under the collector to reduce its series resistance. Bus A circuit or group of circuits which provide a communication path between two or more devices. Byte A set of contiguous binary bits, usually eight (8), which operate on as a unit. A byte can also be a sub-set of a computer word. CA Construction Analysis CCITT Consultative Committee for International Telephony and Telegraphy Channel A region of surface conduction opposite in type from that of the bulk doping of an FET transistor. Chip A single square or rectangular piece of semiconductor material into which a specific electrical circuit has been fabricated. Plural is dice. Also called a die. CMOS Complementary Metal Oxide Semiconductor. A logic family made by combining N- channel and P- channel MOS transistors. Comparator Also called a differential comparator. A circuit that compares two analog inputs and produces a 1 or 0 logic level output, depending on which voltage input is more positive. CPU Central Processing Unit. The part of the computer that fetches, decodes, and executes program instructions and maintains status of results. D/A Converter or DAC A device to convert digital representation into an analog voltage or current level. Data A general term used to denote any or all facts, numbers, letters, and symbols. It connotes basic elements of information which can be processed or produced by a computer. Depletion Device A type of MOSFET which is "on" Development System Microcomputer system complete with peripherals, memory and software, used to write, compile, run and debug application programs for one or more target microprocessors. 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. Diffusion A method of doping or modifying the characteristics of semiconductor material by "baking" wafers of the base semiconductor material in furnaces with controlled atmospheres of impurity materials. DIP Dual-In-line Package. The most common type of IC package, circuit leads or pins extend symmetrically outward and downward from opposite sides of the rectangular package body. Discrete A semiconductor device containing only one active device, such as a transistor or a diode. Donor An impurity that can make a semiconductor N-type by donating extra "free" electrons to the conduction band. The free electrons are carriers of negative charge. Doping The introduction of an impurity into a semiconductor to modify its electrical properties by creating a concentration of N or P carriers. Dynamic RAM A type of semiconductor memory in which the presence or absence of a capacitive charge represents the state of a binary storage element. The charge must be periodically refreshed. EAROM Electrically Alterable ROM, a read-only memory whose contents may be altered on rare occasions through electrical stimuli. ECL Emitter Coupled Logic. A form of current-mode logic in which the output is available from an emitter-follower output stage. EEPROM Electrically Erasable Read Only Memory Enhancement Device A type of MOSFET which requires a control signal input to turn on the device. This device is "off" when no input signal is present. Epitaxial Layer A deposited layer of material having the same crystallographic characteristics as the substrate material. EPROM Erasable PROM, similar to ROM, but enables the user to erase stored information and replace it with new information, when necessary. Most EPROMs are erased through exposure to ultra-violet light. FA Failure Analysis FET Field Effect Transistor Firmware Software in hardware form, referring specifically to microcode in ROM. Flat Pack An IC package which has leads extending from the package in the same plane as the package so that leads can be spot welded to terminals on a substrate or soldered to a printed circuit board. Flip-Flop An electrical circuit having two stable states, on or off. The basic component of a logic or memory circuit. FPLA Field Programmable Logic Array, a PLA can be programmed by the user. Gate The basic digital logic element ... where the binary value of the output depends on the values of the inputs. Gate Equivalent The basic unit of measure for digital circuit complexity, based on the number of elementary logic gates that would have to be interconnected to form the same circuit function. Glassivation The protective coating placed on the entire die surface, usually silicon dioxide or silicon nitride. Also called passivation. HMOS High-performance Metal Oxide Semiconductor Hole The absence of a valance electron in a semiconductor crystal. The movement of a hole is equivalent to the movement of a positive charge. Hybrid Circuit Any combination of two or more of the following in ONE package: active substrate integrated circuit; passive substrate integrated circuit; discrete component. I/O Input/Output relating to the equipment or method used for transmitting information into and out of a computer. IC Integrated Circuit -- a semiconductor die containing multiple elements that act together to form the complete device circuit. IEEE Institute of Electrical and Electronics Engineers ILL Integrated Injection Logic, a bipolar structure characterized by an integrated PNP load device and inverted operation of the NPN logic transistor. Ion Implantation Introduction into a semiconductor of selected impurities via high voltage ion bombardment to achieve desired electrical properties in selected regions. Junction The boundary between a P region and an N region in a semiconductor substrate. LED Light Emitting Diode, a semiconductor device that emits light whenever current passes through it. Linear IC An analog integrated circuit, as opposed to a digital integrated circuit. LS TTL Low-power Schottky Transistor Transistor Logic, the power dissipation of LS TTL is typically 1/5th that of conventional TTL. LSI Large Scale Integration-- LSI devices contain 100 or more gate equivalents or other circuitry of similar complexity. Majority Carrier The mobile charge carrier (hole or electron) that predominates in a semiconductor material. Mask A patterned screen, usually of glass, used to expose selected areas of a semiconductor (that has been covered with a photoresist) to a light source that causes polymerization. MESFET Metalic Schottky Field Effect Transistor, a field effect transistor whose gate structure consists of a metalic Schottky barrier. Microcode A set of control functions performed by the instruction decoding and execution logic of a CPU or microprocessor which defines the instruction repertoire of that computer. Microcomputer A microprocessor complete with stored program memory (read only memory ROM), random access memory (RAM), and Input/Output (I/O) logic. If all functions are on the same chip, this is sometimes called a microcontroller. Microcomputers are capable of performing useful work without additional supporting logic. Microcontroller If all functions, ROM, RAM, I/O are on the same chip, this is sometimes called a microcontroller.. Microelectronics Microscopically small components or circuits made by means of photolithography techniques. Micron Synonymous with micrometer: one millionth of a meter. Microprocessor The basic arithmetic of a computer’s, Central Processing Unit (CPU) Mil One thousandth of an inch, equal to 25.4 microns. Monolithic Device A device whose circuitry is completely contained on a single die or chip MOS Metal Oxide Semiconductor, devices using FETs in which current flow through a channel of N- or P- type semiconductor material is controlled by the electric field around a gate structure. MOSFETs are unipolar devices characterized by extremely high input resistance. MOSFET Metal Oxide Semiconductor Field Effect Transistor MSI Medium Scale Integration, ICs containing ten or more gate equivalents but less than 100. N-Channel MOS A type of MOSFET using electrons to conduct current in the semiconductor channel. The channel has a predominantly negative charge. Op Amp Operational Amplifier, a general purpose IC used as a basic building block for implementation of linear functions. Optical Isolator A circuit-isolation device consisting of an LED and a photodiode or photo transistor in close proximity. Current through the LED causes internal light emission, which current flow in the (isolated) photo transistor. P-Channel MOS A type of MOSFET using holes to conduct current in the semiconductor channel. The channel has a predominantly positive charge. P/O Purchase Order PA Product Analysis Passivation The protective coating placed on the entire die surface, usually silicon dioxide or silicon nitride. Also called glassivation. PCM Pulse Code Modulation, digital transmission of analog signals by sending periodic binary-coded samples of the signal value. PE Product Evaluation Photoresist Light-sensitive material deposited as a uniform thin film on a wafer or substrate. Exposure of specific patterns is performed through masking operations. PIA (typically) the product being investigated PLA Programmable Logic Array, a general purpose logic circuit containing an array of logic gates which can be connected (programmed) to perform various functions. PLL or PL2 Phase-Lock-Loop, a circuit that compares the phase difference between a reference frequency and a voltage-controlled oscillator, whereby the oscillator’s frequency is changed by an error voltage until its frequency coincides with the reference. Probing A term used to describe electrical testing that employs very finely-tipped probes applied sequentially to each of the finished dice on a wafer. PROM Programmable Read Only Memory, a read-only memory which can be programmed after manufacture by external equipment. Typically, PROMs utilize fusible links which may be burned open to produce a logic bit in a specific location. Protocol A set of rules for the formatting and relative timing between communicating processes. RADC Rome Air Development Center RAM Random Access Memory, which stores digital information temporarily and can be changed by the user. It constitutes the basic storage element in a computer. Also called a read/write memory. REID (chips which can replace money as the medium of exchange) ROM Read Only Memory, which permanently stores information used repeatedly such as microcode or characters for electronic display. Unlike RAM, ROM cannot be altered. Schottky 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. 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. Semiconductor A material with properties of both a conductor and an insulator. Common semiconductors include silicon and (expensive) germanium. Silicon Gate A type of MOS in which the gate is made of silicon instead of metal. Faster and denser than metal-gate MOS. Slice A this disc (not disk) of semiconducting material (usually silicon) on which many separate chips can be fabricated and then cut into individual Ics. Also known as wafer. SOCMOS Selective Oxidation Complementary Metal Oxide Semiconductor SOS Silicon-On-Sapphire, a faster MOS technology in which the silicon is grown on a sapphire wafer only where needed. Each device is thus isolated by air or oxide from other devices. SSI Small Scale Integration, Ics containing fewer than ten logic gates. Static RAM A type of Random Access Memory which does not require periodic referesh cycles, as does dynamic RAM. TASC* A classified code name for Cold War-Military Contracts held within ICE which carry classified code numbers (0000 - 4390) TDM Time Division Multiplex, a method of transmitting several data signals over a single line by assigning each to different time slots. Threshold The input voltage at which the output logic level changes state. Transistor The basic solid-state device used to amplify or switch electrical current. TTL or T2L Transistor Transistor Logic UART A commonly-used LSI circuit which serves as a universal (asynchronous) serial communication line controller and data interface for a microprocessor. Unipolar Transistors with majority current conduction (majority carrier) only, as observed in FETs. VLSI Very Large Scale Integration, these devices are Ics that contain 1,000 or more gate equivalents. Wafer A this disc (not disk) of semiconducting material (usually silicon) on which many separate chips can be fabricated and then cut into individual Ics. Also known as slice. 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. Aligner An optical system used in transferring a mask or reticle image to a wafer. Active Component A (non-mechanical) circuit component that has gain or switches current flow, such as a diode, transistor, etc. Actinic The property of radiant energy, especially in the visible and UV spectral regions, by which chemical changes are produced. 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. Alignment Mark A reference mark used in the alignment of the several photomask layers required for a single device or circuit. ALSTTL Advanced Low-power Schottky Transistor Transistor Logic, A fast bipolar logic family with power dissipation about half that of LSTTL. Word A set of binary bits processed by the computer as the primary unit of information. Chip Talk - Current    Chip Talk - Historical

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