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

"Pr-Pz"

practical resolution n		the minimum linewidth that reproduces the mask (or drafting) dimensions faithfully. [SEMI P25-94]
practical use n		in the measurement of photolithographic instruments, the conditions of photoprocess, image geometries, etc., that are required for the intended use of the instrument. [SEMI P25-94]
precipitate n		1 : within a silicon lattice, a region of silicon oxide frequently manifested as an etch pit. [ASTM F1241] Also see crystal lattice. 2 : in a gallium arsenide wafer, a localized concentration of dopant that is insoluble. Precipitate is formed during crystal growth and during any process in which the temperature is sufficient to provide the necessary impurity mobility. [SEMI M10-89]
precision n		the measure of natural variation of repeated measurements. [EIA 557]
preclean carrier n		a plastic vessel used in wet operations to hold wafers. [SEMATECH]
pre-epitaxial treatment n		in sapphire substrates, the process of etching material from a variety of substrates prior to deposition. Hydrogen or another etchant is used for this purpose. [SEMI M4-88]
pre-etch		see linewidth, PR.
preferential etch n		in the manufacture of silicon wafers, a selective etch that etches regions of different crystal strain or conductivity at different rates, used to delineate crystal defects or regions of differing conductivity on wafer surfaces. [SEMI M1-94 and ASTM F1241]
preform n		in metal lid/preform assembly, a solder material of defined volume that is attached to the base material. [SEMI G53-92 ]
premium wafer n		a silicon wafer suitable for particle counting, ion contamination monitoring, and measuring pattern resolution in the photolithography process. [SEMI M24-94]
pre-process treatment chamber (PTC) n		the chamber(s) within the process equipment in which wafers are treated before actual wafer processing (for example, a pre-process wafer degassing chamber). [SEMATECH]
pressure-containing envelope n		that part of a component or specimen that contains pressurized media. [SEMATECH]
pressure decay method n		leak detection determined through pressure loss, over a period of time, within a vessel or piping system. [SEMI F6-92]
pressure reducing valve		see regulator.
primary attribute (or secondary attribute) n		the least significant bit of the lower message ID in the header that indicates whether a block belongs to a primary or a secondary message. [SEMI E4-91]
primary containment n		the first level of containment, that is, the inside portion of the container that comes into immediate contact on its inner surface with the material being contained. [SEMI F6-92] Also see secondary containment.
primary fiducial n		a flat or notch on a semiconductor wafer oriented with respect to a specified crystal plane and used for orientation or alignment of the wafer during device or circuit processing. [SEMATECH]
primary flow standard n		in the calibration of mass flow devices, a device or system that measures flow using a method based on some or all of the primary measurements of length, time, temperature, volume, pressure, or mass. [SEMI E29-93]
primary message n		a complete unit of communication in one direction; an odd-numbered message in which bit 1 of the lower message ID is set to 1. NOTE-A primary message is the first message of a transaction. [SEMI E4-91 and E5-92]
primary orientation flat n		the flat of longest length on the wafer, oriented such that the chord is parallel with a specified low index crystal plane. [ASTM F1241] Also called major flat. Also see secondary flat.
printed circuit board (PCB or PC board) n		a composite of organic and inorganic material, with external and internal conducting or low-resistivity paths that allow mechanical support and electrical connection of components. [SEMATECH]
probability n		in equipment reliability, the likelihood that a given event will occur. [SEMATECH]
probability of failure		see fault probability.
probability plots n		a graphical method of analyzing real data to check for normal distribution. [SEMATECH]
probe n		an instrument used to make electrical contact with an area on a die so voltage or current can be applied to test for functionality. [SEMATECH]
probe damage n		1 : on a substrate, local damage caused by mechanical probing or measurement. Probe damage consists of pitted areas that have spacing equal to that of the probe array. [SEMI Materials, Vol. 3, Definitions for Semiconductor Materials and SEMI M10-89] 2 : in gallium arsenide technology, any damage to the wafer surface caused by mechanical probing or measurement. [SEMI M10-89] Also see probe and crack.
prober n		a piece of hardware that allows a collection of probes to be brought into contact with the die on a wafer for the purpose of testing an integrated circuit. [1994 National Technology Roadmap for Semiconductors]
procedure n		1 : the course of action, or the description of a course of action, taken for the solution of a problem. [SEMATECH] 2 : a step-by-step description of how to perform an operation or process. [SEMATECH] 3 : a named portion of a computer program that performs a specific task. [SEMATECH]
process		1 n : a unique, finite course of events defined by purpose or effect and achieved under given conditions. [SEMATECH] 2 v : to perform operations on data in process. [SEMATECH] 3 adj : fabrication equipment, inspection equipment, and cassette stage equipment used in semiconductor manufacturing. [SEMI E23-91] 4 n : a major group of sequential operations in the manufacture of an integrated circuit. Examples are E-beam lithography, thermal deposition, and reactive ion etch. [SEMATECH]
process capability (Cp) n		for a process under statistical process control, the ratio of the tolerance limits (specification window or upper specification minus the lower specification) of a process to the natural variation of that process (estimated by six times the standard deviation of the process output). [SEMATECH] (The "p" part of the abbreviation is written with a subscript lowercase letter.)
process capability index (Cpk) n		for a process under statistical process control, a measure of process performance similar to process capability (Cp), but adjusted for any variation of the average process output from the stated target value for the process. In a typical process, process capability index is at best equal to process capability, but most commonly, it is less than process capability. A process capability index of at least 1.33 is a desirable objective. [SEMATECH] (The "pk" part of the abbreviation is written with subscript lowercase letters.)
process characterization n		1 : for a process under statistical process control, the sequence of steps performed to provide information about the manufacturing capability and natural variability in a portion of the manufacturing process. [SEMATECH] 2 : in particle counting, the set of events in which a single wafer or batch of wafers is cycled through the tool so an intentional process/chemical change is introduced to the surface or substrate of the wafer; the purpose is to determine particle contributions from the mechanical and process aspects of the process tool. [SEMI E14-93]
process complexity n		the number of steps from wafer start through probe/sort. [SEMATECH]
process control n		the ability to maintain specifications of product and equipment during the manufacturing operations. [SEMATECH]
processed image n		in the measurement of photolithographic instruments, any single geometric form that appears in the realized pattern or topographical variation of a material surface or material constitution, and that is obtained by a physical process of pattern transference from an optical image. [Adapted from SEMI P25-94]
process flow n		the sequence of operations and processes necessary to produce a wafer of functional die. [SEMATECH]
process gas n		in the calibration of mass flow devices, the principal gas that the user requires the device to control or measure. [SEMI E29-93]
process-induced defect (PID) n		defect(s) added to the wafer as a result of a processing step. The PID wafer undergoes the same process sequence as a product wafer. PID wafer data is a closer approximation of actual process defect contributions than particles per wafer pass (PWP) wafer data. [SEMATECH]
processing cycle n		in communications and control of semiconductor manufacturing equipment, a sequence during which all of the material contained in a typical process unit is processed. The processing cycle is often used as a measure of action or time. [SEMI E30-94]
process module n		in a cluster tool, a module that accepts or presents a single wafer inside the module for intratool transport (wafer movement inside the cluster tool). [SEMI E21-94]
process module controller n		a virtual semiconductor device that controls the operation of a cluster tool process module. [SEMATECH]
process outlet valve n		a valve on the low-pressure side of a regulator, used to turn a regulated gas supply on or off (required by the Occupational Safety and Health Association [OSHA]). [SEMI International Standards 1990, Vol. 1, Glossary]
process panel systems		see gas source control equipment.
process pressure n		regulator outlet pressure, or that pressure measured by the outlet gauge. [SEMI International Standards 1990, Vol. 1, Glossary]
process program n		in a cluster tool control system, a set of process module specific instructions that control wafer processing on that process module. [SEMATECH]
process synthesis n		the procedure of gathering knowledge on fabrication processes for semiconductors, organizing this knowledge into models, applying and combining models to optimize fabrication, and using the models to identify needs, to direct research and development, and to innovate both devices and processes. The reduction of process variability is the major goal. [1994 National Technology Roadmap for Semiconductors]
process time n		the length of time required to process one wafer or one batch (for sequential and batch tools, respectively) at a given workstation or through an entire process. [SEMATECH]
process unit n		in communications and control of semiconductor manufacturing equipment, the material that is typically processed as a unit using a single run command, a process program, and so on. Common process units are wafers, cassettes, magazines, and boats. [SEMI E30-94]
process zone n		several processes performed until an acceptable holding point is reached. Approximately 24 hours are required to complete one process zone. Examples are n-well, active area, and passivation resist. [SEMATECH]
product n		1: in equipment reliability, any unit intended to become a functional semiconductor device. This definition includes functional engineering devices. [SEMI E10-92] 2: in gas source control equipment, the gas phase in the cylinder. [SEMI F13-93]
production test n		a set of test vectors and a test program applied using a set of test hardware and optimized to most economically determine whether an integrated circuit contains manufacturing defects. [1994 National Technology Roadmap for Semiconductors]
productive state n		one of the six equipment states or conditions; a period (productive time) during which equipment is performing its intended function. [SEMI E10-92]
productive time n		the total time during which equipment is performing its intended function in producing a product. [SEMI E10-92] Also see productive state.
profilometer n		1 : an instrument for measuring the topographical profile of a surface. [SEMI M1-94 and ASTM F1241] 2 : An instrument for measuring the roughness of a surface by means of a diamond-pointed stylus attached to a coil in an electric field; movement of the stylus across the surface induces a current proportional to the surface roughness. [SEMATECH]
program evaluation review technique (PERT) n		a project planning and management technique that displays all activities on a project so their interdependencies and the critical path are shown. This technique is useful for highly complex technology development projects. [SEMATECH] Also see PERT chart.
programmable array logic (PAL) n		a network of programmable electronic gates used to create a custom logic circuit. [SEMATECH]
programmable factory n		a factory equipped with computer-controlled equipment to provide rapid software-based reconfigurations of process capabilities, equipment capabilities, and product recipes. [SEMATECH]
projection n		on a semiconductor package (plastic or ceramic), leadframe, or preform, an irregularly raised portion of the surface indigenous to the parent material. [SEMI G61-94] Contrast burr, foreign material, and fin.
proof pressure n		in a mass flow controller, the maximum gas pressure the device may be subjected to without permanent damage. Some adjustment may be necessary to make it meet its specified performance when returning to normal operating pressure. [SEMI E28-92]
protective clothing n		articles of apparel to prevent gases, vapors, liquids, and solids from contacting the skin and to prevent them from being inhaled or ingested. This clothing includes self-contained breathing apparatus. [SEMATECH]
protrusion n		1 : in the manufacture of plastic semiconductor packages, the plastic excesses that remain after normal molding, deflashing, trimming, and singulation processing. [SEMI G14-88] Also called parting line protrusions or intrusions. 2 : a surface defect on molded packages that consists of parent material. [SEMATECH] Also called top or bottom protrusions. Also see bubble, blister ceramic, blister metal, and projection. 3 : the dambar section of a leadframe (tab) that remains after dambar trimming when the trimming punch is not totally in line with the lead shoulder by design or misalignment. [SEMATECH] Also called lead shoulder protrusions or intrusions and shoulder width intrusions.
proximity X-ray n		a lithography method using X-ray radiation through a mask close to, but not touching, the resist-coated surface of a silicon wafer. [1994 National Technology Roadmap for Semiconductors]
PSM		see phase shifting mask.
psychotropic adj		acting on, or influencing, the activity of the mind. [SEMATECH]
PTC		see post-process treatment chamber or pre-process treatment chamber.
p-type adj		1 : describes a semiconductor material that has positively charged conductivity (a deficiency of electrons). [SEMATECH] 2 : describes a variety of semiconductive material in which the majority current carriers are holes, formed when acceptor impurities are incorporated into the crystal structure in small concentrations. [ASTM F1241]
pullback n		on a semiconductor package, the linear distance between the edge of a cavity cut into a layer of ceramic and the first measurable glass or metallization layer interface coated onto the top surface of that layer. The total pullback may be the result of the high temperature processing required to manufacture the package or to coat the surface. It may also be the result of design considerations. [SEMI G61-94]
pure water n		water suitable for use in semiconductor processing because of the very small level of impurities. Resistivity in pure water is high because the conductive impurities are at a low level. [SEMATECH]
purge gas inlet (PGI) valve n		a valve dedicated to the introduction of purge gas into a purge manifold. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
purge manifold n		a piping/valving system designed to replace an undesirable gas in a piping system or vessel with a desirable gas by venting the undesirable gas and subsequently introducing the desirable gas. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
purge volume n		the internal volume of piping, valves, and other components to be purged of unwanted gas or vapor. The volume of a given system can include different portions of the system, depending upon the operation to be performed. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
PVD		see physical vapor deposition.
PWP		see particles per wafer pass.
pyramid n		a structure displaying \|111\| facets that appears on surfaces after epitaxial growth. DISCUSSION-A pyramid originates at the interface of the substrate and the epi layer and is due to various imperfections at the beginning of epi growth. [ASTM F1241] Also called growth hillock. Also see hillock and mound.
pyrogenic steam n		water vapor generated by combining hydrogen and oxygen in the furnace working chamber to produce high purity steam. [ASTM F1241]
pyrolysis n		an irreversible chemical decomposition caused by heat, usually without oxidation. [ASTM E176-90]
pyrophoric adj		describes materials that ignite spontaneously in air at or below 54.55C (1305F). [SEMI F6-92]
pyrophoric gas n		a gas that, upon contact with air or oxygen, will ignite spontaneously at or below a temperature of 54.5 degrees C (130 degrees F). [SEMI S4-92]
pyrophoric material n		a chemical that will spontaneously ignite in the air at or below a temperature of 54.5 degrees C (130 degrees F). [SEMI S4-92]

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