Access Time

Time interval between the instant that a piece of information is sent to the memory device and the instant it returns.

Alignment

The correct positioning of a mask or reticle relative to a wafer.

Ambient

Room temperature

Binary

Numbering system using two as a base and requiring only two symbols: 0 and 1.

Bit

(Memory Bit) Short for 'Binary Digit.' The smallest piece of data (a '1' or '0') that a computer recognizes.

Combinations of 1s and 0s are used to represent characters and numbers.

Burn-in

The process of exercising an integrated circuit at elevated voltage and temperature. This process accelerates failure normally seen as "infant mortality" in a chip. (Those chips that would fail early during actual usage will fail during this process. Those that pass this test have a life expectancy much greater than that required for normal usage.

Byte

A number of binary bits, usually eight, that represent one numeric or alphabetic character.

Capacitance

The property of a circuit element that permits it to store an electrical charge.

Capacitor

A discrete device that stores an electrical charge on two conductors separated by a dielectric.

Cell

A tiny area within the memory array that actually stores the bit in the form of an electrical charge.

Cleanroom

The super clean environment in which semiconductors are manufactured. The lower the rating, the cleaner the facility. These rooms typically have hundreds of thousands of particles less per cubic foot than the normal environment.

CMOS

Complementary Metal Oxide Semiconductor. A MOS device containing both N-channel and P-channel MOS active elements. One of two basic processes (MOS and Bipolar) used to fabricate integrated circuits.

CPU

Central Processing Unit. The computer module in charge of retrieving, decoding, and executing instructions.

Design Rules

A set of rules establishing minimum dimensions of a transistor and minimum spacing between adjacent components.

Die

A single rectangular piece of semiconductor material onto which specific electrical circuits have been fabricated; refers to a semiconductor which has not yet been packaged.

Dielectric

A material that conducts no current when it has voltage applied to it. Two dielectrics used in semiconductor processing are silicon dioxide and silicon nitride.

Diffusion

The standard procedure for doping silicon by heating wafers in a furnace from 400 to 1,150 degrees C in an atmosphere of dopant atoms.

Digital

Indicates the representation of data by a series of bits or discrete values, such as 0s and 1s.

Doping

The introduction of an impurity into a semiconductor to modify its electrical properties.

DRAM

Dynamic Random Access Memory. A type of memory component. 'Dynamic' means the device's memory cells need to be periodically recharged. Information stored in the memory cells, as a positive or negative charge, is accessed randomly.

Etch

Removal of specific material (such as portions of a given layer) through a chemical reaction.

Flash

A nonvolatile programmable semiconductor memory product. Flash devices retain the contents of their memory when the power is turned off.

Flat Pack

A flat, rectangular IC package type with the necessary leads projecting from the sides of the package.

Geometries

(Device) sizes within a device referring to the layout of components and interconnects on the die.

IC

Integrated Circuit.

A tiny complex of electronic components and their connections produced on a slice of material such as silicon. Commonly referred to as a die or chip.

Ion Implant

The process of introducing selected impurities into a semiconductor via high-voltage ion bombardment to achieve desired electrical properties in selected regions.

KGD

(Known Good Die) Fully tested chips that are ready for bonding into multi-chip modules.

Lithography

The transfer of a pattern or image from one medium to another, as from a mask to a wafer.

Logic

The circuits used to control operation of IC devices.

Mask

A chrome and glass pattern for a layer of the wafer used in the photolithography process.

Megabit

One million binary pieces (bits) of information.

Micron

A unit of measure equivalent to one-millionth of a meter, synonymous with micrometer.

Mil

One-thousandth of an inch, equal to 25.

4 microns.

Ministack

A three dimensional capacitor structure built between two layers of polysilicon. The three dimensional structure uses vertical and horizontal surfaces to increase total capacitor surface area facilitating large capacitance in a small area.

PC Board

Printed circuit board. The board(s) used in a computer system onto which semiconductor components are connected.

Photolithography

The process used to transfer a pattern or image from the masks to a wafer. The process uses a photosensitive emulsion and light.

Photoresist

A material that prevents etching or plating of the area it covers.

PLCC

Plastic leaded chip carrier. A type of semiconductor package.

Planar

A simple flat capacitor built between silicon and polysilicon layers.

Resistor

A semiconductor device that provides resistance to the flow of electricity.

Reticle

A piece of glass with a chrome pattern for several die, used in the photolithography process.

Semiconductor

A solid crystalline substance whose electrical conductivity falls between that of a conductor and an insulator.

Shrink

Reduction in die (chip) size.

Silicon

A nonmetallic element used in the semiconductor industry as a substrate for multiple layers of material, built to form electrical circuits. Silicon is grown from a crystal to form a cylinder shaped 'log. ' Slicing the logs into sections 1/40 of an inch thick creates bare wafers.

SIMM

Single In-line Memory Module.

A high-density DRAM package alternative consisting of several plastic leaded chip carriers (PLCC) connected to a single printed circuit board (PC board). SIMMs provide an upgrade vehicle for future generations of DRAMs without having to redesign the PC board.

SRAM

Static Random Access Memory. An integrated circuit similar to a DRAM which requires no constant refreshing or recharging. It retains stored information as long as power is applied to the computer, hastening information retrieval process time.

Subassemblies

Two or more individually replaceable items integrated to form a system.

Surface Mount

PC board assembly technique for high density manufacturing using TSOP, PLCC, and SOJ packages.

Transistor

A semiconductor device that uses a stream of charge carriers to produce active electronic effects.

Wafer

A thin disk (or slice) of silicon on which many separate chips can be fabricated and then cut into individual die.

Yield

Number of acceptable units (die) produced on each wafer compared to the maximum possible.