SEMATECH Dictionary of Semiconductor Terms

A-Am | An-Az | B | C-Ch | Ci-Com | Con-Cz | D-De | Df-Dz | E-En | Eo-Ez | F-Fl
Fm-Fz | G | H | I | J-K | L | M-Mes | Met-Mz | N | O | P-Ph | Pi-Pq | Pr-Pz | Q | R
S-Se | Sh-So | Sp-Sta | Ste-Sz | T-Th | Ti-Tz | U-V | W-Z

"M-Mes "

macro instruction n		an instruction in a source language designated to be replaced by a defined sequence of instructions in the same source language; it may also specify values for parameters in the defined instructions. [SEMATECH]
macro level n		in automated material movement, the level of material movement that involves coordination by the host but may not require knowledge of the physical process used to accomplish the material transfer. [SEMI E32-94]
macroscopic adj		large enough to be seen by the unaided eye. [SEMATECH]
macroscratch n		a scratch that is visible to the unaided eye either under incandescent (high intensity) or fluorescent (diffuse) illumination. [ASTM F1241] Contrast microscratch.
maintainability, equipment		see equipment maintainability.
maintenance n		the act of sustaining equipment in a condition to perform its intended function. [SEMI E10-92]
major flat		see primary orientation flat.
majority carrier n		a type of charge carrier constituting more than one-half the total charge carrier concentration (for example, holes in p-type material). [SEMI M1-94 and ASTM F1241] Contrast minority carrier.
make-up air n		the amount or percentage of fresh air delivered or mixed with recirculating air on a normal cycle of air by volume. [SEMATECH]
malaise n		a feeling of general discomfort, distress, or uneasiness. [SEMATECH]
manual override n		a mechanism incorporated into a remotely actuated valve that provides for manual closing and locking. [SEMI F4-90]
manufacturing automation protocol (MAP) n		a set of instructions or rules designed to control computer communications and to provide systems status and control in a factory environment. [SEMATECH]
manufacturing specialist n		an operator/technician capable of operating, maintaining, and repairing multiple manufacturing equipment sets and interfacing with engineers, maintenance, facilities, and systems personnel. [SEMATECH]
manufacturing support item (MSI) n		any supply item used in the cleanroom that indirectly supports the manufacturing process, excluding process fluids, equipment, and the facility (for example, wafer boxes, cleanroom gloves, and wipers). [SEMATECH] .
marks, saw		see saw marks.
mask n		1 : a flat, transparent plate that contains the photographic image of wafer patterns necessary to define one process layer. [SEMATECH] 2 : a selective barrier to the passage of radiation or matter. [ASTM F127-84] Also called etched metal mask or any specific mask type. Contrast photomask.
mask, bimetal n		a mask formed by chemically etching openings in a metal film or plate that is protected from the etchant in certain areas by a second metal. The second metal is generally applied to the first by electro-forming or coating. [ASTM F127-84]
mask, etched metal n		a mask formed by chemically etched openings in a metal film or plate where it is not protected from the etchant by photoresist or other chemically resistant material. [ASTM F127-84]
mask level n		a numbered mask in a sequence that includes device patterns, test patterns, and alignment patterns. [SEMATECH]
mask, metal on glass n		an optical mask comprising a glass substrate selectively covered by a thin opaque metal layer; a type of photomask. [ASTM F127-84]
mask, mirror image n		a mask having its geometric configuration rotated 180 degrees about a Y-Y axis with respect to an original. [ASTM F127-84]
masks, device series of n		all masks necessary to produce a specific device or circuit. [ASTM F127-84] t
mask, trimetal n		a mask formed by etching a metal protected by a third metal in certain areas. [ASTM F127-84]
mass balance n		the identification and quantization of the products of a process or reaction to where all of the expected products are quantitatively accounted for. [1994 National Technology Roadmap for Semiconductors]
mass flow controller (MFC) n		a self-contained device (consisting of a transducer, control valve, and control and signal-processing electronics) commonly used in the semiconductor industry to measure and regulate the mass flow of gas. [SEMI E29-93]
mass flow controller calibration pressure, inlet and outlet n		in a mass flow controller, the inlet and outlet pressure at which the device was calibrated. [SEMI E28-92]
mass flow meter (MFM) n		a self-contained device, consisting of a mass flow transducer and signal-processing electronics, commonly used in the semiconductor industry to measure the mass flow of gas. [SEMI E29-93]
mass flow of gas n		in mass flow controllers and gas meters, the mass of gas per unit of time flowing in a closed fluid channel. [SEMI Mass Flow Controllers Committee] Also see standard volumetric flow, standard pressure, standard temperature, mass flow controller, and mass flow meter.
master n		in message transfer, the block transfer designation for the equipment (the intelligent system that communicates with a host computer). NOTE-The equipment is designated as the master and the host as the slave; this convention is based upon the assumption that the equipment is less able to store messages than the host. [SEMI E4-87]
master drawing		see composite drawing.
mastery learning		see criterion-referenced instruction.
material n		in automated material movement, discrete objects that may be transferred to and from equipment. These objects may include product, carriers, reusable fixtures, and so on. [Adapted from SEMI E32-94] Also see transfer object.
material control system (MCS) n		the software program used to control the routing and transfer of material (wafers, cassettes, or boxes) within an automated material handling system. [SEMATECH]
material hazard index (MHI) n		a numeric value used for ranking chemical production materials to determine the level of controls necessary for regulation. MHI is determined by dividing the equilibrium vapor concentration (EVC) of a material at 25 degrees C by the level of concern (LOC) value for that material. [SEMI F6-92]
material location n		in automated material movement, a physical position on a piece of equipment at which a transfer object may reside. Many material locations may be accessed directly through a port, but this is not a requirement. Some material locations internal to the equipment may not be accessible by a transfer agent. [SEMI E32-94]
material on the surface n		in flat panel display substrates, small transparent glass particles that are adhered or fused to the glass substrate surface. [SEMI D9-94]
material safety data sheet (MSDS) n		1 : written or printed material concerning a hazardous material that is prepared in accordance with the provisions of 29 CFR 1910.1200. (See UFC "88" 9.115.) (Form OSHA 20) [SEMI S2-91] 2 : the descriptive data provided on a data sheet recommended by the Occupational Safety and Health Administration (OSHA) to provide information regarding the hazards of materials to prevent and respond to emergency situations. [SEMATECH]
material transport module n		a physical unit that moves wafers from place to place within a cluster tool. [SEMATECH]
matrix n		1 : a group of entities that have dissimilar primary functions that interface and cooperate to achieve a common purpose; includes people, machines, and organizations. [SEMATECH] 2 : a two dimensional array of numbers commonly used for vector mathematics. [SEMATECH]
matrix management n		executive, supervisory, and administrative direction that facilitates the accomplishment of a common purpose by dissimilar groups. [SEMATECH]
maximum baking temperature n		in a mass flow controller, the highest temperature to which the mass flow controller or its components in contact with the gas can be heated in accordance with a specified baking procedure. The specified baking process will not impair the performance characteristics per the manufacturers specifications. [Adapted from SEMI E18-91]
maximum focal plane deviation n		in the measurement of wafer flatness, the largest of the absolute values of the focal plane deviations (FPD). [SEMI M1-94]
maximum operating pressure n		in a mass flow controller, the maximum inlet pressure at which the mass flow controller may be operated. NOTE-Operation is permitted up to this inlet pressure, but performance is not specified above normal operating pressure. [Adapted from SEMI E28-92]
maximum overrange pressure n		in a mass flow controller, the maximum gas pressure to which the mass flow controller (MFC) may be subjected without degrading specified performance. When returned to normal operating pressure, the MFC must require no adjustment to return to specified performance. [SEMI E28-92]
maximum permissible exposure n		in safety threshold limit values, the exposure limit for nonionizing radiation, according to ANSI Z136.1 and ANSI C95.1. [SEMI S2-93]
maximum recommended flow n		for regulators, a recommended flow rate specified by the manufacturer. This value is typically within the control range of the regulator prior to the drop-off seen in the flow curve. [SEMATECH]
may v		a term indicating that a provision is neither required nor prohibited by a specification. [SEMI F1-90]
MCBA		see mean cycles between assists.
MCBF		see mean cycles between failures.
MCM		see multichip module.
MCS		see material control system.
MDL		see minimum detectable limit.
mean n		the sum of a group of measurements divided by the number of measurements; the average. [SEMATECH]
mean cycles between assists (MCBA) n		the number of equipment cycles between assists; total equipment cycles divided by the number of assists during those cycles. [SEMATECH]
mean cycles between failures (MCBF) n		the average number of equipment cycles between failures; total equipment cycles divided by the number of failures during those cycles. [SEMATECH]
mean focus n		in the measurement of photolithographic instruments, the Z-axis position representing the area average focal surface for point-like objects in the optical image. [SEMI P25-94]
mean moving range control chart		see -MR (mean-moving range) control chart.
mean (productive) time between assists (MTBAp) n		the average time during which the equipment performed its intended function between assists; productive time divided by the number of assists during that time. [SEMI E10-92] (The "p" part of the abbreviation is written with a subscript lowercase letter.)
mean (productive) time between failures (MTBFp) n		the average time during which the equipment performed its intended function between failures; productive time divided by the number of failures during that time. [SEMI E10-92] (The "p" part of the abbreviation is written with a subscript lowercase letter.)
mean time between assists (MTBA) n		the number of hours producing per week, divided by assists per week; the average number of hours producing until an assist is required. [SEMATECH] Contrast mean (productive) time between assists.
mean time between failures (MTBF) n		the number of hours producing per week, divided by failures per week; the average number of hours producing until a failure is encountered. [SEMATECH] Contrast mean (productive) time between failures.
mean time off line (MTOL) n		the average time required to return the equipment to a condition in which it can perform its intended function when downtime is incurred. The sum of all downtime (scheduled and unscheduled) during a specified period, divided by the number of downtime incidents during that period. [SEMI E10-92]
mean time to repair (MTTR) n		the average time required to correct a failure and to return the equipment to a condition in which it can perform its intended function. The sum of all repair time incurred during a specified period (including equipment and process test time, but not including maintenance delay) divided by the number of failures during that period. [SEMI E10-92]

measured leak rate n		the rate of leakage of a given gas distribution system, measured under specified conditions and employing a specified test gas. The measured leak rate shall be corrected to standard leak rate by multiplying by the ratio of 101.3 kPa to the absolute value of the pressurizing helium. [SEMATECH]
mechanical characterization n		in particle counting, the set of events in which a single wafer or batch of wafers are cycled through the tool so that no intentional process/chemical changes are introduced to the surface or substrate of the wafer; the purpose is to determine particle contributions from the mechanical wafer movement throughout the process tool. [SEMI E14-90]
mechanical leak n		in the measurement of mass flow controller leak rates, a leak caused by a physical crack, pit, scratch or other imperfection in a sealing surface, or contamination or debris on the seals. [Adapted from SEMI E16-90]
mechanical strength n		in the manufacture of photolithographic pellicles, the physical condition a pellicle must meet to withstand a specified force from a blow-off gun without suffering any damage to the film due to stretching or breakage. [SEMI P5-94]
median n		in a group of measurements arranged from lowest to highest, the middle value if the number of measurements is odd. If the number of measurements is even, the median is the average of the two middle values. [SEMATECH]
median surface n		of a semiconductor wafer, the locus of points in the wafer equidistant between the front and back surfaces. [ASTM F1241]
median tolerance limit n		designates the concentration of a toxic material at which 50% of the test organisms (usually aquatic organisms) survive. [SEMATECH]
medium scale integration (MSI) n		the placement of between 10 and 100 active devices on a single die. [SEMATECH]
megabyte (Mbyte) n		1,048,576 () bytes, or 1,024 kilobytes of iinformation or storage space. [SEMATECH]
megasonic n		a method of cleaning or etching through which the liquid media being employed is mechanically agitated with frequency acoustic energy to improve control or to accelerate the process. [1994 National Technology Roadmap for Semiconductors]
melting temperature n		in semicrystalline polymers, the temperature at which the crystalline phase becomes amorphous. [SEMATECH]
membrane probes n		integrated circuit test probes that are built on a flexible membrane. The membrane, with the probes, is brought into contact with a wafer through the flexure of the membrane. [1994 National Technology Roadmap for Semiconductors]
memory n		a circuit function that provides capacity for data or information storage. [SEMATECH]
menu n		a list of options visually presented on a terminal by a computer program to allow a user to select a course of action. [SEMATECH]
menu-driven adj		relying heavily on menus and providing the user with total control over the manner in which the program operates. [SEMATECH] Contrast data-driven.
merge v		to combine two ordered arrays in such a manner as to form a third, similarly ordered array. A good example is a list merged with a letter to create personalized letters. [SEMATECH]
message n		a complete unit of communication in one direction. [SEMI E4-91] Also see block.
message fault n		in communications and control of semiconductor manufacturing equipment, a condition that occurs when the equipment receives a message that it cannot process because of a defect in the message. [SEMI E30-94]
message header n		in SECS-II, information about a message passed by the message transfer protocol. NOTE-The content of the message header consists of device ID, stream and function, reply requested, transaction timeout, and (optionally) multiple open transactions. In SECS-I, the related term "header" refers to the 10-byte header in each block. [SEMI E5-92]
message ID n		a 15-bit field in the header; used in the process of message identification. NOTE-The message ID identifies the format and content of the message being sent. The exact message content is equipment-dependent, and a particular message is one of many possible for the particular device. [SEMI E4-91]
message protocol n		in message transfer, the SECS-I message protocol uses the services of the block transfer protocol to send and receive messages. (The block transfer protocol is used by a serial line to establish the direction of communication and to provide the environment for the passing of message blocks.) A message consists of the message data, together with the following information from the header in each block: the R-bit, device ID, W-bit, message ID, and system bytes. [SEMATECH]
message section n		the section of a safety sign that contains those words that clarify the nature and severity of the hazard, so as to provide the rationale for evasive actions. It must also state the appropriate evasive actions. Whenever possible, these messages should be chosen from common usage or community acceptance. [SEMI S1-90]
message service		see service.

Back to index…