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

"N"

NAK n		"Incorrect Reception" handshake code. NOTE-NAK (derived from Not AcKnowledged) is one of the four standard handshake codes used in block transfer protocol. The code NAK (00010101) corresponds to the ASCII code that has the same pattern.[SEMI E4-91]
nameplate gas n		in mass flow devices, the gas, as labeled on the product, intended to be controlled or measured. [SEMI E29-93]
nanogram (ng) n		one billionth () of a gram. [SEMATECH]
nanometer (nm) n		one billionth () of a meter; used in the measurement of the wavelength of light. [SEMATECH]
nanosecond (ns) n		one billionth () of a second. [SEMATECH]
National Electric Code (NEC) hazardous voltage n		as defined by the NEC, voltage greater then 50 V. (Article 720) [SEMI S2-93]
National Electric Code (NEC) high voltage n		as defined by the NEC, voltage greater than 600 V. (Article 710) [SEMI S2-93]
National Electric Code (NEC) low voltage n		as defined by the NEC, voltage between 50 and 600 V. [SEMI S2-91]
National Electric Code (NEC) safe voltage n		as defined by the NEC, voltage between 50 and 600 V. [SEMI S2-93]
National Fire Protection Association (NFPA) n		a voluntary membership organization that promotes and improves fire protection and prevention and establishes safeguards against loss of life and property by fire. [SEMATECH]
national laboratories n		a subset of federal laboratories concerned with research and innovation; the nine national laboratories are under the direction of the U.S. Department of Energy. Examples are Oak Ridge, Sandia, and Los Alamos. [SEMATECH] Contrast federal laboratories.
nebula		see haze.
nebulosity		see haze.
NEC		see National Electric Code.
negative mask		see photomask, negative.
neoplastic effects n		production of tumors. [SEMATECH]
neutral beam n		a stream of uncharged particles. [SEMATECH]
nick		see chip.
nitric acid (HNO₃) n		a strong, colorless or yellowish liquid oxidant that is highly corrosive and a potential fire hazard. This acid is prepared by the action of sulfuric acid on nitrates and by the oxidation of ammonia. Nitric acid is used to clean silicon wafers and etch metals. [SEMI C1.12-90]
nitride etch n		an etch process whereby unprotected portions of a silicon nitride layer are eroded to expose the initial oxide layer beneath the nitride. [SEMATECH]
nitrogen (N₂) n		normally a diatomic gas, but also a cryogenic liquid (a liquid at low temperature). Its vapors are odorless, tasteless, and nonflammable. Nitrogen is used in purging, blanketing, pressurizing systems, and cooling systems. It also is used as a carrier gas in chemical vapor deposition and at ambient temperature for sintering and annealing. [SEMI C3.5-88]
nitrogen trifluoride (NF₃) n		a toxic, odorless, and nonflammable gas that is a strong oxidizer and supports combustion. This gas is used as a source of fluoride ions in plasma processes. [SEMI C3.39-89]
nitrous oxide (N₂O) n		an oxidizing, colorless, liquefied gas with a sweetish odor. It is toxic to humans when breathed. Nitrous oxide is used in the chemical vapor deposition of silicon dioxide and in plasma processes. [SEMI C3.13-88]
nodules n		in metal lid/preform assembly, lumps of plating extending above the surface of the lid. [SEMI G53-92]
noise-limited height resolution n		in surface characterization by noncontact optical profilometry, the root-mean-square height fluctuation around the mean of the measurement of the height for any given point on the surface. [SEMATECH]
nominal feature dimension n		the linear dimension of interest, such as the linewidth or contact hole width. [SEMI P19-92]
noncritical seal area n		on a semiconductor package that uses a lid or cover to effect the seal, the area of the sealing surface outside the critical sealing area. [SEMI G58-94] Contrast critical seal area.
nonflammable adj		incapable of being easily ignited or of burning with extreme rapidity when lighted. [SEMATECH]
nonisotropic		see anisotropic.
nonliquefied compressed gas n		a gas, other than a gas in solution, that under the charging pressure is entirely gaseous at a temperature of 21.1 degrees C (70 degrees F). [SEMI C3-94]
non-return to zero (NRZ) n		a digital waveform that undergoes only one transition per clock cycle. [1994 National Technology Roadmap for Semiconductors]
nonscheduled state n		one of the six equipment states or conditions; a period of nonscheduled time during which equipment is not scheduled to be utilized in production. Such periods include offline training, unworked shifts, weekends, and holidays. [SEMI E10-92]
nonscheduled time n		any period that is not scheduled to be utilized, such as offline training, unworked shifts, weekends, and holidays. [SEMI E10-92] Also see nonscheduled state.
nonsymmetrical valve n		a valve not identical with respect to center line and not having similar flow and pressure characteristics in either direction. [SEMATECH]
nonuniformity n		of transmission lines and waveguides, the degree with which a characteristic quantity (for example, impedance) deviates from a constant value along a given path. (Copyright 1993 IEEE. All rights reserved.)
normal astigmatism n		in the measurement of photolithographic instruments, the difference in Z-axis position at each image site between the sagittal focal surface and the tangential focal surface. Astigmatism is a map of scalar values over the (X,Y) coordinates of the image field. [SEMI P25-94]
normal operating differential pressure n		in a mass flow controller, the range of differential pressure required by the device to meet its stated performance specifications. [SEMI E28-92]
normal operating pressure, inlet and outlet n		in a mass flow controller, the pressure range within which the device meets its stated performance specifications. [SEMI E28-92]
normal operating temperature n		in a mass flow controller, the temperature range within which the influence of ambient temperature on the performance is stated. [SEMI E18-91]
normal surface n		of a component test sample, an area of the sample that does not exhibit any visible defect when viewed under a scanning electron microscope, used to provide a baseline for comparison with any area exhibiting a defect. [SEMATECH]
notch n		1 : an unexpected intrusion or reduction of linewidth in patterned geometries. May also be a V-shaped intrusion into the perimeter of a wafer. The intrusion is used to align the wafer during process. [SEMATECH] 2 : on a semiconductor wafer, an intentionally fabricated indent of specified shape and dimensions oriented such that the diameter passing through the center of the notch is parallel with a specified low index crystal direction. [SEMI M1-94 and ASTM F1241]
NRZ		see non-return to zero.
n-type adj		1 : describes a semiconductor material that has negatively charged conductivity (a surplus of electrons); material with free-carriers of electricity dominated by negatively charged ions. [SEMATECH] Also see conductivity type. 2 : a variety of semiconductive material in which the majority current carriers are electrons, formed when donor impurities are incorporated into the crystal structure in small concentrations. [ASTM F1241]
nucleation n		the replating step in which a catalytic material, often a palladium or gold compound, is absorbed on a surface to act as sites for initial stages of deposition. [ASTM B374-93]
number of anomalies n		in microscopic analysis of metallic surface condition, the total number of defects per photomicrograph. [SEMATECH] Also called number of defects.
number of defects		see number of anomalies.

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