IC Knowledge - Glossary

Glossary of Integrated Circuit Terminology - M

Magnetically Enhanced Reactive Ion Etching - a type of reactive ion etching where a magnetic field is used to enhance ion generation in the plasma. MERIE has a higher density of ions relative to RIE without magnetic enhancement.
Magnification - the optical image size divided by the object size.
Majority Carrier - for a doped semiconductor one type of carrier, either holes or electrons is present in much higher concentration than the other type of carrier, this is a called the majority carrier.
Makeup Air - air brought in from outside of a facility used to replace exhaust air. Typically in cleanroom applications, makeup air is brought into the cleanroom at a higher rate than exhaust air is removed to provide positive pressure insuring that contaminants are pushed out of the room.
Marangoni Dryer - system that uses a solvent film to displace water from a wafer surface drying the wafer. Marangoni dryers use very little solvent and produce high quality low particle wafer drying.
Mask - a glass plate with a pattern of transparent and opaque areas used to photolithographically create patterns on wafers. A mask is commonly used to refer to a plate that has a pattern large enough to pattern a whole wafer at one time. See also, reticle.
Mask Layer - a method of characterizing the complexity of a process. A mask layer is all of the process steps associated with a particular mask.
Mass Flow Controller - a device used to measure and control the flow rate of a gas or vapor.
Master Plate - a mask used to photographically create other masks. Material Cost - the cost for the materials that actually make up the product that is shipped. In wafer fabrication, the wafer is the material, in assembly, the leadframe and epoxy are the material. Material costs do not include materials consumed to perform the fabrication process, those materials are included in overhead.
MCT - MOS Controlled Thyristor - a thyristor controlled by a MOS gate electrode.
MCU - see Microcontroller
Mega - a prefix meaning one million, (x10⁶), symbol M. Megasonic - the use of 700-1,000 kilohertz sonic energy to aid in particle removal during wet cleans. Megasonic energy creates acoustic streaming, dislodging particles down into the sub micron range.
Memory - a device that can store information for later retrieval.
MERIE - see Magnetically Enhanced Reactive Ion Etching.
MESFET - Metal Shottky FET - a field effect transistor that has a metal shottky barrier for a gate. Commonly used for high frequency application on compound semiconductors.
Metal Gate - a type of MOS device that uses metal as the gate electrode.
Metal Oxide Semiconductor - a type of field effect transistor that uses silicon dioxide as the insulating layer between the gate electrode and the channel region.
Metalization - a layer of metal typically utilized to interconnect different devices that make up an integrated circuit.
Metastable - a state of stability that is barely stable. Metastable states may be easily stimulated to become unstable.
Metrology - equipment or process used to produce a measurement.
MICFET - Minority Injected Carrier Field Effect Transistor - similar to a MOSFET except minority carriers are also used for conduction increasing the device efficiency.
Micro - a prefix meaning one millionth (x10^-6), symbol is µ.
Microcontroller - single purpose processing units designed to execute small control programs, sometimes in real time. The program is frequently stored on the microcontroller in an area of nonvolatile memory.
Microlithography - the process of photographically forming very small patterns.
Micrometer - one millionth of a meter (1x10^-6), symbol µm.
Micron - an older term for micrometer.
Microperipheral - chips designed to support microprocessors in personal computers. Microperipherals manage memory, provide vaious input-output connections, etc.
Microprocessor - general purpose processing units designed to execute very large and complex programs, usually not in real time.
Microwave - electromagnetic radiation with a wavelength of 30 centimeters to 1 millimeter. Mid Ultraviolet Light – electromagnetic waves with a wavelength of 300 to 350 nanometers.
Mil - one thousandth of an inch (x10^-3 inch), equal to 25.4µms.
Miller Indices - a set of three integers to specify crystal planes.
Milli - a prefix meaning one thousandth (x10^-3), symbol is m.
Millimeter - one thousandth of a meter (1x10^-3), symbol is mm.
Minienvironment - a localized clean environment created around a tool, or only within a tool where wafers will be exposed to the atmosphere. Wafers are moved from one minienvironment equipped tool to the next minienvironment equipped tool in sealed containers and only exposed to the atmosphere inside of the clean environment created inside the tool.
Minority Carrier - the carrier type in the minority. For a doped semiconductor, one type of carrier either holes or electrons is present in much smaller concentrations than the other type of carrier, this is called a minority carrier.
MMIC - Monolithic Microwave IC - an analog IC with on-chip capacitors and inductors design to work at microwave frequencies.
MNOS - Metal Nitride Oxide Semiconductor - the interface between the silicon dioxide and silicon nitride layers may is used to trap charge creating a type of non-volatile memory. The gate of the device is biased during inject or remove electrons into the oxide - nitride interface from the underlying substrate. Commonly used to make EEPROMs.
Mobility - the velocity of a carrier inside a material under the influence of an electric field.
Molecule - two or more atoms bonded together.
Monochromatic Light - light of a single wavelength or very narrow bandwidth. Monochromatic light is made up of a single color of light.
Monolithic Device - a device containing a complete circuit.
MOS - Metal Oxide Semiconductor - a type of semiconductor device fabricated with a conducting layer and a semiconductor layer separated by an insulating layer. MOS semiconductors are unipolar devices that use either holes or electrons for conduction, but not both at once, i.e. they are not bipolar devices.
MOS Capacitor - a capacitor created by a metal and a semiconductor separated by an insulator. By performing a CV plot on an MOS capacitor a number of characteristics of the semiconductor and insulator may be measured. An MOS capacitor is the simplest manifestation of the MOS system.
MOSFET - Metal Oxide Semiconductor Field Effect Transistor. A type of transistor where a conductive electrode is separated from the semiconductor surface by an insulating layer, typically silicon dioxide. Varying the voltage on the conductive electrode controls the flow of current along the semiconductor surface.
MPR - see Microperipheral
MPU - see Microprocessor
MSI - Medium Scale Integration - an integrated circuit consisting of >30 and <1,000 transistors.
MTBF - Mean Time Between Failure - the average time between failures for a given piece of equipment or equipment set.
MTTR - Mean Time To Repair - the average time it takes to repair a given piece of equipment or equipment set
Multi Level Metal - more than one layer of metal interconnect.
Murphy Model - one type of probability model for converting defect density to projected yield.