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

"S-Se"

sacrificial etchback n		the practice of cleaning a silicon wafer surface by oxidizing the surface and completely removing the oxide layer by etching and thereby removing surface contaminants. [1994 National Technology Roadmap for Semiconductors]
safe n		free of conditions that can cause occupational illness, injury, or death to personnel, damage to or loss of equipment or property, or damage to the environment. [SEMI S2-93]
safety sign		see sign.
safe voltage		see National Electric Code (NEC) safe voltage.
sagittal focal surface n		in the measurement of photolithographic instruments, the focal surface determined by examining only sagittal lines. [SEMI P25-94] See sagittal lines.
sagittal lines n		in the measurement of photolithographic instruments, an evaluative line pattern in which the lines lie along a radius to the optical axis. [SEMI P25-94]
salicide n		a self-aligned silicide; a silicon or polysilicon reaction with a metal to form a new compound self-aligned to the desired device component structure, such as the gate, source, and drain regions. [SEMATECH]
sample angle n		in electron spectroscopy for chemical analysis, the angle of the surface with respect to a horizontal axis, which is defined as zero. [SEMATECH]
sample flow rate n		in particle contribution testing, the volumetric flow rate drawn by the counter for particle detection. The counter may draw higher flow for other purposes (for example, sheath gas). [SEMATECH]
sample tilt angle n		in scanning electron microscopy, the angle that the sample plane makes with a line normal to the incoming electron beam. [SEMATECH]
sample volume flow n		the actual amount of liquid being monitored in an optical particle counter, measured in units of liters or milliliters per minute. [SEMATECH]
sampling distance n		the lateral distance between areas to be measured for characterizing a surface. [SEMATECH]
sampling number n		the number of measurements to be made over a given surface. [SEMATECH]
sampling time n		in particle contribution testing, the time increment over which counts are recorded. [SEMATECH] .
sapphire n		in silicon on sapphire technology, a single-crystal aluminum oxide substrate having a definite orientation that allows epitaxial deposition. [SEMI M3-91] Also see epitaxy and epitaxial layer.
saucer pits		see shallow etch pits.
saw-blade defect n		1 : on semiconductor wafers, a roughened area visible after polishing with a pattern characteristic of the saw blade travel. [ASTM F1241] Also see saw marks. 2 : a depression in the wafer surface made by the blade, which may not be visible before polishing. [SEMI M10-89]
saw exit chip n		in gallium arsenide technology, an edge fragment on a wafer broken off at the point at which the saw completed its cut of the wafer. A saw exit chip is typically straight or arc shaped, not irregular, and sometimes can be confused with the orientation flats. [SEMI M10-89] Contrast saw exit mark.
saw exit mark n		in silicon technology, a ragged edge at the periphery of a wafer consisting of numerous adjacent small adjoining edge chips resulting from saw blade exit. [ASTM F1241] Also see saw marks, saw exit chip.
saw-kerf		see scribe line.
saw marks n		on a wafer, surface irregularities in the form of a series of alternating ridges and depressions in arcs, the radii of which are the same as those of the saw blade used for slicing. [ASTM F1241] Also see saw exit mark.
scaling n		the proportional adjustment of the dimensions of an electronic device while maintaining the electrical properties of the device; results in a device either larger or smaller than the unscaled device. [SEMATECH]
scaling laws n		the set of rules describing how dimension-reduction in integrated circuits interrelate to each other and to the electrical behavior of the resulting devices. Scaling laws are used to predict the impact of size reduction on minimum power supply voltage and on device speed and power, as well as on the geometry of the structures. [1994 National Technology Roadmap for Semiconductors]
scan		1 n : in scanning tunneling microscopy, movement of the microscope tip relative to sample surface, continuously in one direction. Contrast raster. [SEMATECH] 2 v : to move the microscope tip continuously in one direction. [SEMATECH]
scan area n		in scanning tunneling microscopy, area defined by successive, side-by-side scan lengths. [SEMATECH]
scan direction n		in scanning tunneling microscopy, the direction in which the tip or sample is continuously scanned, orthogonal to the Y-direction, in the sample plane. [SEMATECH] Also called X-direction. Also see scan.
scan length n		in scanning tunneling microscopy, the distance from start to end of a single scan. [SEMATECH] Also called scan width.
scan path n		a linkage of registers in an integrated circuit with associated control mechanisms that enables the registers to be operated as a shift register in addition to their normal mode of operation. This permits the registers to be controlled and observed during test mode, greatly enhancing testability. [1994 National Technology Roadmap for Semiconductors]
scanning electron microscope (SEM) n		a device that displays an electronically scanned image of a die or wafer for examination on a screen or for transfer onto photographic film; displays a higher magnification than an optical microscope. [SEMATECH]
scanning tunneling microscope (STM) n		an instrument for producing surface images with atomic scale lateral resolution, in which a fine probe tip is raster scanned over the surface and the resulting tunneling current is monitored. [SEMATECH]
scan rate n		in scanning tunneling microscopy and atomic force microscopy, the speed at which the tip or cantilever moves relative to the surface. [SEMATECH]
scan width		see scan length.
scattering n		the diffraction of light by particles or the reflection of light by particles or surfaces. [SEMATECH]
scatterometer n		an instrument used to study the nature of scattered light and determine information about a wafer's surface (for example, film thickness, refractive index, and surface contamination). [SEMATECH]
scenario n		in communications and control of semiconductor manufacturing equipment, a group of SECS-II messages arranged in a sequence to perform a capability. Other information may also be included in a scenario for clarity. [SEMI E30-94]
scheduled downtime n		the total time during which equipment is not available to perform its intended function because of planned downtime events. [SEMI E10-92] Also see scheduled downtime state and equipment states.
scheduled downtime state n		one of the six equipment states, or conditions; a period during which equipment is not available to perform its intended function because of planned downtime events. [SEMI E10-92]
Schottky barrier diodes n		a semiconductor diode that is formed by contact between a semiconductor layer and a metal coating; it has a nonlinear rectifying characteristic. Hot carriers are emitted from the metal coating that is the diode base; since majority carriers predominate, there is essentially no injection or storage of minority carriers to limit switching speeds. Also known as a hot-carrier diode. [SEMATECH]
SCOE		see SEMATECH Center of Excellence.
scoring n		in plastic molding preforms, marks, grooves, scratches, or notches with definite length, width, and depth physical characteristics. [SEMI G49-93]
scrape n		in cofired ceramic packages, the irregular removal of a deposited layer or surface layer from a base material by a shearing action from another surface, such that the base material is exposed over an extended area. [Adapted from SEMI G61-94]
scratch n		on semiconductor wafers, a shallow groove or cut below the established plane of the surface, with a length to width ratio greater than 5:1. [ASTM F1241] Also see macroscratch and microscratch.
screening test n		a test or combination of tests intended to remove unsatisfactory items or those items likely to exhibit early failures. (Copyright 1993 IEEE. All rights reserved.)
scribe line n		a space on a wafer between die. The space must be large enough to allow separation of the die by cutting or breaking, without damage to the die. [SEMATECH] Also called kerf, saw-kerf, and street.
scuff n		in flat panel display substrates, the marring of the glass substrate surface, leaving a milky white, grayish, or matte appearance and having appreciable width. [SEMI D9-94] Contrast with scratch.
scum n		resist residue located in a window or along the foot of patterned geometry. [SEMATECH]
scumming n		residual resist located in areas that should have been cleaned in the develop operation. [SEMATECH]
SDS		see sodium dodecyl sulfate.
seal area n		on a semiconductor package, the area designated for sealing a cover or lid to a cofired ceramic package, or a cap to a cerdip or cerpack base. In the case of a cofired package, the seal area may be either bare ceramic for glass sealing or a metallized area for solder sealing. [SEMI G61-94]
seal cap n		an end closure or plug used to block the open end of a tube or fitting to allow a test specimen to be pressurized with air. [SEMATECH]
sealing n		the joining of the package case header (chip carrier base or substrate) with the cover or lid into one sealed unit. [SEMATECH]
seal ring n		in metal lid/preform assembly, the area designated for attaching the lid to the package by welding or soldering techniques. [SEMI G53-92]
seat n		a part of a valve body in which the poppet or diaphragm assembly rests to control media flow. [SEMATECH]
seating plane n		in plug-in type devices, such as dual inline packages (sidebrazed or cerdip) or pin grid arrays, the plane formed by the three lowest shoulders on the leads or pins as measured from the bottom of the package. The seating plane holds the package off the circuit board to which it is mounted. This gap allows solder flux and residues to be cleaned after soldering the leads and, in some cases, allows for sufficient cooling air flow around the device. A prescribed force is used to hold the device in the mounting holes when the seating plane is to be measured. [SEMI G61-94] Also see standoff.
secondary attribute		see primary attribute (secondary attribute).
secondary containment n		1 : a safeguarding method used to prevent unplanned releases of toxic or hazardous compounds into uncontrolled work areas. [SEMATECH] 2 : level of containment that is external to and separate from primary containment. Secondary containment is a method of safeguarding used to prevent unauthorized releases of toxic or hazardous gases into uncontrolled work areas. Secondary containment means those methods or facilities in addition to the primary containment system. [SEMI F6-93]
secondary flat n		a flat of length shorter than the primary orientation flat, whose position with respect to the primary orientation flat identifies the type and orientation of the wafer. DISCUSSION-In some cases, one or more nonstandard "secondary" flats are specified to identify other attributes of the wafer. [ASTM F1241] Also called minor flat.
secondary message n		the second message of a transaction; an even-numbered message, which has bit 1 of the lower message ID set to 0. [SEMI E4-91 and E5-92] Contrast primary message.
SECS message service (SMS) n		in communications and control of semiconductor manufacturing equipment, a SEMI standard (SEMI E13) that provides an alternative to SECS-I to be used when sending SECS-II formatted messages over a network. [SEMI E30-94]
SECS message subset n		the set of SECS-II messages required to define the scenarios. This selected group is smaller in number than the current SEMI SECS-II. [SEMI E30-94]
Seebeck emf		see thermal emf.
seed n		in flat panel display substrates, a gaseous inclusion less than 0.5 mm long. [SEMI D9-94]
segregation of gases n		the National Fire Codes use the terms, "separated," "segregated," and "isolated" when referring to storage of hazardous materials. Segregated storage is generally defined by National Fire Protection Association (NFPA) Standards as "stored in the same room, but physically separated by space or barrier from incompatible materials." [Adapted from SEMI S4-92]
self-checking bar code n		in the bar code marking of silicon wafers, a bar code that uses a checking algorithm that can be applied against each character, so substitution errors can only occur if two or more independent printing defects appear within a single character. [SEMI T1-93]
self-consistent top-down design n		a design methodology that starts at the conceptual or abstraction level with a set of behavioral descriptions of the final product. All of the design elements and constraints are supported by accurate models and carried through all levels of design hierarchy. Changes and/or corrections made to the design at any level of implementation will propagate, both upward and downward, through all the levels of the design hierarchy. Constraints such as manufacturability, reliability, or power are applied at the highest possible level. [SEMATECH] Also called hierarchical design methodology.
self-clocking n		in the bar code marking of silicon wafers, a bar code in which the number of modules, bars, and spaces is the same in each character. [SEMI T1-93]
self-contained regulator n		a regulator that contains a mechanical spring that, when compressed by rotation of a control knob, imposes a force proportional to the desired outlet-gas pressure. The spring area is separated from the media by a static-sealed diaphragm, a dynamically sealed piston, or a bellows. [SEMI International Standards 1990, Vol. 1, Glossary] Also see regulator.
self-doping		see autodoping.
SEM		see scanning electron microscope.
SEMASPEC n		a SEMATECH specification, method, rule, guideline, or description established and controlled by SEMATECH. [SEMATECH]
SEMATECH Center of Excellence (SCOE) n		a SEMATECH-funded research center at one of several designated U.S. universities that conducts basic and applied research in science and technology areas that are beneficial to the semiconductor industry. [SEMATECH]
semiconductor n		an element that has an electrical resistivity in the range between conductors (such as aluminum) and insulators (such as silicon dioxide). Integrated circuits are typically fabricated in semiconductor materials such as silicon, germanium, or gallium arsenide. [SEMATECH]
Semiconductor Equipment and Materials International, Inc. (SEMI) n		an international trade organization with membership from companies that supply equipment, materials, and services used in the semiconductor manufacturing industry. [SEMATECH]
Semiconductor Equipment Technology Center (SETEC) n		a national equipment design center at Sandia National Laboratories, established as a cooperative effort between SEMATECH and Sandia. [SEMATECH]
Semiconductor Industry Association (SIA) n		the U.S. trade association of the semiconductor industry. [SEMATECH]
Semiconductor Research Corporation (SRC) n		a corporation funded by the semiconductor industry to manage university research for its members. The SRC manages SEMATECH's university research program (SCOEs), since SEMATECH is an SRC member. [SEMATECH]
Semiconductor Safety Association (SSA) n		an independent organization of safety professionals from semiconductor manufacturing companies. [SEMATECH]
SEMI Equipment Communications Standard 1 (SECS-I) n		1 : a SEMI Equipment Communications Standard (SEMI E4) that addresses the mechanism for conveying information over an electrically controllable medium such as wire, fiber-optic cable, or electromagnetic transmission. [SEMATECH] 2 : a standard that specifies a method for a message transfer protocol with electrical signal levels based on EIA RS232-C. [SEMI E30-94]
SEMI Equipment Communications Standard 2 (SECS-II) n		1 : a SEMI Equipment Communications Standard (SEMI E5) that addresses how information should be structured for conveyance; provides syntax and semantics. [SEMATECH] 2 : a standard that specifies a group of messages and the respective syntax and semantics for those messages relating to semiconductor manufacturing equipment control. [SEMI E30-94]
SemiSPIN n		the Semiconductor Software Process Improvement Network, which is a leadership forum for the exchange of software improvement ideas and experience. [SEMATECH]
send-ahead n		a wafer exposed and developed to verify correct focus, critical dimensions (CDs), and alignment prior to committing the entire lot to exposure. [SEMATECH]
sender n		the end of the SECS-I link sending a message. [SEMI E4-91]
sending port n		in an automated material transfer, the port from which a transfer object is to be removed. [SEMI E32-94]
sensitivity n		in the leak rates of mass flow controllers, the smallest standard leak rate that an instrument, method, or system is capable of measuring under specified conditions. [SEMI E16-90] Also called minimum detectable leak rate.
sensitize v		the application of a compound or treatment to an object to increase the effect of a process or action on that object. [SEMATECH]
sensitized photoplate n		a photoplate coated with a radiation-sensitive substance. [ASTM F127-84]
sensitizer n		a material that on first exposure causes little or no reaction in man or test animals, but which on repeated exposure may cause a marked response not necessarily limited to the contact site. [SEMATECH]
separation of gases n		the National Fire Codes use the terms, "separated," "segregated," and "isolated" when referring to storage of hazardous materials. Separation as defined by National Fire Protection Association (NFPA) 49 is "storage within the same fire area, but separated by as much space as practical, or by intervening storage from compatible materials." [Adapted from SEMI S4-92]
service n		in equipment communications, a function offered to a user by a provider. A service consists of a sequence of service primitives, each described by a list of parameters. A service excludes definition of message structure and protocol. [SEMI E39-94] Also called message service.
service provider n		in equipment communications, an application responsible for providing services to service users. NOTE-There may be one or more service users concurrently accessing a single service provider. It is the responsibility of the service provider to provide its services transparently to each service user. [SEMI 2309, proposed]
service user n		in equipment communications, any application that uses the services. [SEMI 2309, proposed]
sessile cells n		in determining surface associated biofilms of ultrapure water distribution systems, anchored cells attached to a surface. [SEMATECH]
SETEC		see Semiconductor Equipment Technology Center.
set point n		in mass flow controller testing, the electrical input signal to the device that sets the desired value of the controlled flow. [SEMI E17-91]
set point sensitivity n		in testing regulator performance characteristics, the minimum pressure increment that can be repeatedly set on a regulator. [SEMATECH]
set point stability n		of a regulator, the variation in the outlet pressure that occurs under steady state conditions, within the regulator's control range. [SEMATECH]
set point tolerance n		in equipment exhaust systems, the range (±) of static pressure within which an exhaust enclosure will perform efficiently and effectively. [SEMI S6-93]
settling time n		in mass flow controller testing, the interval between the set point step change and the period during which the actual flow remains within the specified band. [SEMI E17-91]
setup and test n		total time for which the equipment is not available to perform its intended task because of scheduled setup and test time, including daily checklists, etch rate tests, defect density tests, and oxygen cleans. [SEMATECH]

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