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

"O"

object n		1 : a software entity that is uniquely identifiable and encapsulates behavior, attributes, and state. An object performs an action (behavior) upon receipt of a message, and may, in turn, send messages to other objects. [SEMATECH] 2 : in equipment communications, an entity with a specific set of data and behaviors. An object may be physical or conceptual. [SEMI E39-94]
object attribute n		in equipment communications, information concerning an object. For example, for object type "equipment": manufacturer, model type, and serial number. [SEMI E39-94] Also called attribute.
object code n		output from a compiler or assembler suitable for processing to produce executable machine code. [SEMATECH]
object identifier n		in equipment communications, a set of one or more items of information concerning a particular instance of an object of a given type that together uniquely distinguish that instance from all other instances of that object within a defined scope. [SEMI E39-94] Also see object instance.
object instance n		in equipment communications, an instantiation of an object type. An object type is like a template, while an object instance is the actual object. For example, an actual and specific optical stepper installed in a particular fab is an instance of the type "optical stepper." [SEMI E39-94] Contrast instance.
objective n		of a microscope, the primary magnifying system, consisting of a system (generally of lenses, less frequently of mirrors) forming a real, inverted, and magnified image of the object viewed. [ASTM E175-82] Also see eyepiece.
object model n		in equipment communications, a static graphic model of objects to show structure-the identity of objects, their attributes and operations, and their relationships with one another. [SEMI E39-94]
object-oriented adj		describes a perspective that views the elements of a problem or solution by decomposition into objects and object relationships. [SEMATECH]
object-oriented analysis n		the process of describing and understanding an end user's problem by identifying natural classes of objects and their relationships. [SEMATECH]
object-oriented design n		the process of selecting and describing a computer-based solution to an end user's problem by using natural and artificial objects to describe the interfaces, configurations, and operations of the computer-based system solution. [SEMATECH]
object-oriented programming system (OOPS) n		a system composed of a programming language and programming tools. It allows the encapsulation of data elements and of the operations that apply to them into clusters, called objects, that have well defined interfaces to the other objects in the system. [SEMATECH]
object-oriented technology n		the languages, environments, tools, and methodologies used to build software applications based on objects. [SEMATECH]
ocular		see eyepiece.
odor threshold n		the lowest concentration of a material's vapor (or a gas) in air that can be detected by smell; frequently expressed as a percentage of a panel of test individuals. [SEMATECH] .
offgassing		see outgassing.
offset n		in a plastic molded package, the difference in the bottom cavity position from a leadframe datum when compared to design. This measurement ignores leadframe tolerances. [SEMI G54-93] Also called cavity-to-frame offset. Also see mismatch and overlap.
ohms per square n		the electrical resistance of a vacuum metallized coating measured on a sample in which the dimensions of the coating width and length are equal. The ohm-per-square measurement is independent of sample dimensions. [ASTM C740-82]
oil canning n		in metal lid/preform assembly, lid concavity after sealing. [SEMI G53-92]
oligotroph n		an organism able to subsist at low (< 1 ppm) carbon concentrations. [SEMATECH]
on board emission control n		emission reduction hardware integrated within the equipment footprint. [SEMI S2-93]
OOP		see object-oriented programming system.
open bubble n		in flat panel display substrates, a gaseous inclusion so close to the surface that it is obviously open, or one so close to the surface that it may be broken open with the point of a soft lead pencil. [SEMI D9-94] t
opening		see isolated space.
open message n		a multiblock message for which all the blocks (each of which consists of a header and up to 244 bytes of data) have not been received. [SEMI E4-91]
open secondary containment n		secondary containment with an open-ended annular space. This annulus must be directed to a system designed to handle the contained hazardous production material. [SEMI S6-92]
open systems approach n		standardized procedures for the exchange of information between terminals, computers, people, and networks. [SEMATECH]
open transaction n		a transaction in progress. NOTE-A transaction is a paired message that consists of a request and its reply. [SEMI E4-91]
operating temperature limits n		in a mass flow controller, the temperature range within which operation is permitted, but performance is not specified beyond the normal operating temperature. If the instrument is operated outside these limits, damage may occur. [Adapted from SEMI E18-91]
operation n		the performance of one or more steps within a process on one machine without operator intervention. Examples are resist application and soft bake, align/expose, develop/rinse/spin dry, sputter etch, and sputter deposition. [SEMATECH]
operational script n		in communications and control of semiconductor manufacturing equipment, a collection of scenarios arranged in a sequence typical of actual factory operations. Example sequences would include system initialization powerup, machine setup, and processing. [SEMI E30-94]
operational uptime n		the percentage of time the equipment is in a condition to perform its intended function during the period of operations time. Operational uptime (percentage) equals the quotient of equipment uptime and operations time multiplied by 100. This calculation is intended to reflect the overall operational performance of a piece of equipment. [SEMI E10-92]
operational utilization n		the percentage of productive time during operations time, not including nonscheduled time. Operational utilization (percentage) equals the quotient of productive time and operations time multiplied by 100. This calculation is intended to be used for equipment utilization comparisons between operations that have different configurations of work shifts. [SEMI E10-92]
operations time n		in equipment reliability, the total time minus nonscheduled time. Total time is all time, at the rate of 24 hours per day and seven days a week, during the period being measured. Nonscheduled time is any period not scheduled to be utilized. [SEMI E10-92]
operator n		in communications and control of semiconductor manufacturing equipment, a human who operates the equipment to perform its intended function (for example, processing). The operator typically interacts with the equipment through the equipment-supplied operator console. [SEMI E30-94]
optical properties n		in flat panel display substrates, the ratio of transmitted light versus incident light. [SEMI D9-94]
optical proximity correction n		a data treatment designed to compensate for proximity effects resulting from stepper optical proximity effects. It is generally viewed as a technique for improving critical dimension control. [SEMATECH]
optical shrink n		the simplest procedure for reducing the size of the die to fit more die on a wafer. This procedure does not result in consistently functional die. [SEMATECH]
optic axis n		of a doubly refracting crystal, that direction through the crystal along which no double refraction occurs. [ASTM F1241]
orange peel n		on a semiconductor wafer, large-featured roughened type of surface visible to the unaided eye. [ASTM F1241] Also see spiral.
orientation n		of a single crystal surface, the crystallographic plane, described in terms of its Miller indices, with which the surface is ideally coincident. NOTE-In semiconductor single crystals, where the surface of a wafer cut from the crystal usually corresponds closely (within a degree or several degrees) to a low index plane, such as a {100} or {111} plane, the surface orientation is frequently described in terms of the maximum angular deviation of the mechanically prepared surface from the low index crystallographic plane. [ASTM F1241]
orientation convention n		of a flat panel display substrate, the method used to describe the pattern surface's quadrant location relative to a fixture, and its rotational position relative to the fixture banking pins. [SEMI D4-94]
orientation corner n		in flat panel display, the corner of a substrate that identifies the pattern surface and rotational orientation. [SEMI D4-94]
origin n		of a dot matrix, the physical center point of the dot in the cell common to the primary border row and secondary border column. [SEMI T2-93]
originator n		the creator of an original primary message (first message of a transaction). [SEMI E5-92] Contrast interpreter.
orthogonality n		the measure of perpendicularity between the X- and Y-axis geometries printed on a substrate. [SEMATECH]
orthogonal misorientation n		l : on polished monocrystalline silicon wafers and test slices cut intentionally off-orientation, the angle between the projection of the vector normal to the wafer surface onto the {111} plane and the projection on that plane of the nearest <110> direction. [SEMI M1-94] 2 : on {100} polished monocrystalline gallium arsenide wafers cut intentionally off-orientation, the angle between the projection of the vector normal to the wafer surface onto the {100} plane and the projection on that plane of the nearest direction. [SEMI M9-90] Also see crystallographic notation.
other health hazard n		a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. The term "health hazard" includes chemicals that are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents that act on the hematopoietic system, and agents that damage the lungs, skin, eyes, or mucous membranes. [SEMI S4-92]
other regulated material (ORM) n		a U.S. Department of Transportation classification of a particular hazardous material used to label the material for transport. [SEMATECH]
outboard test n		in determining test gas leak rate for gas distribution system components, a test of the leakage outward when the external pressure is less than the internal pressure of the test component. [SEMATECH]
outgassing n		1 : the release of adsorbed or occluded gases or water vapor, usually by heating, in a vacuum. 2 : the release of gaseous contamination by facilities, equipment, or tools in a cleanroom; often called offgassing. [SEMATECH]
outlet gauge n		a pressure gauge, usually affixed to the body of the system regulator on the low pressure side, that measures the pressure after reduction by the pressure regulator. [SEMI International Standards 1990, Vol. 1, Glossary]
outlet mass flow controller calibration pressure		see mass flow controller calibration pressure, inlet and outlet.
outlet normal operating pressure		see normal operating pressure, inlet and outlet.
outlet pressure n		in a mass flow controller, the pressure at the device's outlet fitting. [SEMI E28-92]
out-of-control actions n		a list of steps to be taken when the process is flagged as out-of-control. The desired outcome of executing the steps in the specified order is that the process comes back into control. [SEMATECH]
overcoat		see passivation.
overcut v		to exceed the boundary of an image with the cutting tool during scribing. [ASTM F127-84]
overhang n		on a ceramic semiconductor package, the horizontal extension of the sealing glass past the vertical wall of a cavity cut into the ceramic layer on which the glass is printed. [SEMI G58-94]
overlap n		1 : the area that extends beyond the die edge on artwork; added to ensure continuity in step and repeat. [ASTM F127-84] 2 : the difference in length and width between the top and bottom cavities of a plastic package encapsulation mold. [SEMI G54-93] Also see mismatch.
overlay (OVL)		1n : a computer program segment not permanently maintained in in ternal storage. [SEMATECH] 2 n : the technique of repeatedly using the same areas of internal storage during different stages of a computer program. [SEMATECH] 3 v : to load a segment of a computer program into a storage area occupied by parts of the program not currently needed. [SEMATECH] 4 n : the precision with which successive masks can be aligned with previous patterns on a silicon wafer. [1994 National Technology Roadmap for Semiconductors] 5 n : in semiconductor wafers and flat panel display substrates, a vector quantity defined at every point on the wafer or substrate. It is the difference, O, between the vector position, , of a substrate geometry, and the vector position of the corresponding point, , in an overlaying pattern, which may consist of photoresist. [Adapted from SEMI P18-92 and D8-94]
overlay accuracy n		relative deviation of pattern position between two masks. [SEMI P21-92]
overlay, interfield n		the overlay at the reference point in each exposure field; the center of the lens is chosen to be a reference point. [SEMI P18-92]
overlay, intrafield n		the overlay within an exposure field, relative to the overlay at the center of the lens reference location. [SEMI P18-92]
owned object n		in equipment communications, an object that is a component of, contained in, or supervised by, another object. The owned object is said to be owned by the other object. [SEMI E39-94]
ownership n		in automated material movement, an equipment's physical control of the transfer object. The equipment is said to "own" a transfer object from the time the object is transferred into one of its ports until it is transferred out of the equipment. [Adapted from SEMI E32-94]
oxidation n		a high-temperature chemical reaction in which the silicon of the wafer surface reacts with oxygen or water vapor to form an oxide such as silicon dioxide, typically at temperatures greater than 800 degrees C. [SEMATECH]
oxide (Ox) n		a dielectric, or nonconducting film, grown or deposited on the surface of a wafer. [SEMATECH]
oxide defect n		an area of missing oxide on the back surface of back-sealed wafers discernible to the unaided eye. [ASTM F1241]
oxide etch n		an etch process in which unprotected areas of the oxide layer are eroded by use of a chemical to expose the underlying layer. [SEMATECH]
oxides of nitrogen n		nitrogen and oxygen compounds that react with the moisture in the respiratory tract to produce acids that corrode and irritate tissue. Chronic exposures to low levels can cause irritation, cough, headache, and tooth corrosion. Examples are NO, N2O, and NO2. [SEMATECH]
oxidizer gas n		a gas that will support combustion or increase the burning rate of a combustible material with which it may come in contact. [SEMI S4-92]
oxygen (O₂) n		a colorless, odorless, nontoxic, and oxidizing gas that supports combustion. Oxygen is used in the chemical vapor deposition of silicon dioxide, as a source for oxidation, as a reactant to produce high-purity water, and in plasma etching and stripping. [SEMI C3.22-88]

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