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

"T-Th"

T1 n		in the block transfer protocol, the receive intercharacter timeout (T1). NOTE-A timeout detects communications failures. T1 limits the time between receipt of characters within a message block after the length byte has been received. It continues to limit the time until the receipt of the second checksum byte. [SEMI E4-91]
T2 n		in the block transfer protocol, the protocol timeout. NOTE-A timeout detects communications failures. T2 limits the time between (1) the sending of ENQ (the code for "Request to Send") and the reception of EOT (the code for "Ready to Receive"); (2) the sending of EOT and the reception of the length byte; and (3) the sending of the checksum byte and the reception of any character. [SEMI E4-91]
T3 n		in the message protocol, the reply timeout. NOTE-A timeout detects communications failures. T3 is a limit on the length of time that the message protocol will wait after the last block of a primary message has been sent and before the arrival of the first block of the reply. A transaction timeout occurs when T3 expires. [SEMI E4-91]
T4 n		in the message protocol, the inter-block timeout. NOTE-A timeout detects communications failures. T4 is a limit on the time interval between the successful receipt of a block in a multiblock message and the receipt of the subsequent block of the same message. [SEMI E4-91]
tack weld n		in metal lid/preform assembly, small spot welds, generally located in the corners, that are used to attach the preform to the lid. [SEMI G53-92]
take-off angle (TOA) n		in electron spectroscopy for chemical analysis, the angle of the lens axis with respect to the sample plane. [SEMATECH]
tangential focal surface n		in the measurement of photolithographic instruments, the focal surface determined by examining only the tangential lines. [SEMI P25-94]
tangential lines n		in the measurement of photolithographic instruments, an evaluative line pattern in which the lines lie perpendicular to a radius to the optical axis. [SEMI P25-94]
tape automated bonding (TAB) n		a method of making an electrical interconnection between a die and a substrate by using conductors on beam tape that are mass bonded to bumps on the integrated circuit in a single operation. [SEMATECH]
taper n		of a semiconductor wafer, the linear component of the variation in thickness across a wafer, indicated by the angle between the best fit plane to the front surface and the ideally flat back surface of the wafer. [ASTM F1241] Also called wedge.
target audience n		the audience that needs to be advised of a hazard. [SEMI S1-90]
task analysis n		an organized approach to analyzing a job or a task in which all the elements of the activity are defined, including knowledge requirements, skills, equipment, tools, materials, sequencing, number of steps, resources, safety issues, related procedures, and training. [SEMATECH]
Taylor tray n		a brown-clay soil formation that is shifting and highly expansive. [SEMATECH]
TC		see thermocouple.
T/C		see thermocompression.
TCA		see 1,1,1-trichloroethane.
TCP/IP n		abbreviation for transmission control protocol/internet protocol; the standard accepted by the U.S. Department of Defense for governing information interchange and communications between host computers. [SEMATECH]
technology driver n		leading-edge process/product technology that drives development of next-generation equipment, unit processes, and manufacturing techniques. Essential elements include high-volume diagnostic techniques for accelerated learning and a large revenue stream with which to fund research and development and capital investment. [SEMATECH]
technology libraries n		the codified form of the information required by computer-aided programs that completely describes the circuit family being used. These library parameters include (but are not limited to) items such as delay equations, power characteristics, geometric shapes, and simulation models. [1994 National Technology Roadmap for Semiconductors]
temperature coefficient ( ) n		in regulator performance testing, the average rate of change of the regulator's set point per degree of temperature change, that is, Pa per 1 degree C. The temperature coefficient may be positive (set point increases with increasing temperature) or negative (set point decreases with increasing temperature) or both. [SEMATECH]
temperature coefficient curve n		in regulator performance testing, a plot of set point versus temperature from which the temperature coefficient can be determined. [SEMATECH]
temperature cycling n		a stress test in which components are repeatedly exposed to extreme hot and cold temperatures. [SEMATECH]
temperature- sensitive parameter (TSP) n		in the thermal testing of semiconductor packages, the temperature-dependent electrical characteristic of a semiconductor junction in the device under test that can be calibrated with reference to temperature and subsequently used to detect the junction temperature of interest. [SEMI G43-87]
template n		1 : a model that describes a pattern of program input to be recognized or a pattern of output to be produced. [SEMATECH] 2 : a format, overlay, or form used to generate consistent product. Examples are a reticle or mask in semiconductor manufacturing, a standard format for documents, and a computer keyboard overlay. [SEMATECH]
tensile adj		having to do with the longitudinal stress applied to lengthen a test object. [SEMI F7-92]
teratogen n		a chemical agent that causes congenital malformations in a developing embryo or fetus. [ASTM E609-81]
terminal n		1 : on a semiconductor package, an external lead or contact pad for electrical connection between the inner circuitry of the package and exterior circuitry on a circuit board or substrate. [SEMATECH] 2 : in data communication, a device, usually equipped with a keyboard and display device, capable of sending and receiving information. [SEMATECH]
terminal-based linearity n		in the linearity of mass flow devices, the maximum deviation of the calibration curve from a straight line that intercepts the calibration curve at upper and lower input range values. [SEMI E27-92]
terminal emulator n		a computer program that runs on a computer and causes the computer to act like a specified terminal. [SEMATECH]
terracing n		a network of contours that are associated with pyramid-like defects on epitaxially deposited surfaces and are related to the orientation of the surface. [ASTM F1241]
testability n		the ease with which tests can be generated for and applied to a given circuit. [1994 National Technology Roadmap for Semiconductors]
testability metrics n		measures that determine whether an integrated circuit is easy or hard to test; alternatively, they can measure how effectively a given set of test vectors tests the integrated circuit for a particular type of fault. [1994 National Technology Roadmap for Semiconductors]
tester pattern generation (TPG) n		the generation of a program that runs on an integrated circuit hardware tester (integrated circuit tester). The purpose of this program is to permit test vectors to be applied to the pins of the integrated circuit, and measurements made to determine the performance of the integrated circuit. [1994 National Technology Roadmap for Semiconductors] Also called tester program generation.
test flow rate n		in fluid distribution system component testing, volumetric flow at test pressure and temperature. [SEMATECH]
test method n		a definitive procedure for the identification, measurement, and evaluation of a material, product, system, or service that produces a test result. [ASTM D4392-87]
test pattern		see pattern, test.
test pressure n		in fluid distribution system component testing, pressure immediately downstream of the test component. [SEMATECH]
test strategies n		choosing which techniques from those available that will be used as part of a specific chip design. [1994 National Technology Roadmap for Semiconductors]
test techniques n		any methods used for the expressed purpose of testing integrated circuits. Examples include built-in self test (BIST), automatic test pattern generator (ATPG), static current test (), and boundary scan. [1994 National Technology Roadmap for Semiconductors]
test vectors n		sequences of signals applied to the pins of an integrated circuit to determine whether the integrated circuit is performing as it was designed. [1994 National Technology Roadmap for Semiconductors]
test vehicle n		a fully functional circuit used to demonstrate process integration and control. [SEMATECH]
test wafer		see wafer, test.
tetrachlorosilane		see silicon tetrachloride.
tetrafluoromethane		see carbon tetrafluoride.
theoretical cycle time n		the summation of cycle times of individual value-added operations at the minimum known process time for a single unit of product for a manufacturing sequence. This definition of theoretical cycle time includes the load, process, and unload times and does not include transportation, set up, queue, downtime, metrology, or production test, which would be considered process inefficiencies. [SEMATECH]
theoretical equipment capacity n		potential number of product wafers the equipment could process during total time if there were no nonscheduled time, unscheduled or scheduled downtime, engineering or stand-by time allowed. (This can also be viewed as the maximum processing rate for a given piece of equipment.) [SEMATECH] Contrast throughput.
thermal deposition n		a process in which chemical dopants are introduced onto a silicon wafer in a controlled atmosphere at temperatures typically greater than 950 degrees C. [SEMATECH]
thermal emf n		the net electromotive force (emf) set up in a thermocouple under conditions of zero current. [ASTM F1241] Also called Seebeck emf.
thermal oxidation n		the reaction of silicon with oxygen at temperatures near 1000 degrees C to form silicon dioxide. [SEMATECH]
thermal shock n		a thermal stress test in which the package is alternately dipped in hot and cold (fluorocarbon) fluid. [SEMATECH]
thermal shrinkage n		in flat panel display substrates, the shrinkage of a substrate caused by the relaxation of thermal stress and the structure change that occur when the substrate is heat treated along a specific thermal profile. Usually thermal is described with L/, where L is the amount of change, and shown as L= - L. is the length of material before heat treatment and L is after heat treatment. [Adapted from SEMI D9-94]
thermal transient testing n		a technique for evaluating the integrity of semiconductor die attachment. Semiconductor die are sensitive to voids in the die attach medium-organic resin, metal alloys, or solders. The voids impede the flow of heat away from the die to the package or substrate and may also create cracks in the die when it is exposed to large temperature variations in thermal testing. Tests may be conducted on unencapsulated thermal test chips or on active devices. [SEMATECH]
thermal transition n		in the thermal testing of fluorocarbon tube fitting connections, a change from a specific elevated fluid temperature down to room temperature and then to an elevated temperature higher than previously tested, with the entire process repeated under multiple temperature conditions. [SEMI F11-93]
thermocompression (T/C) bonding n		a process that involves the use of pressure and temperature to join two materials by interdiffusion across the boundary. [SEMATECH]
thermocouple (TC) n		a pair of dissimilar metal wires; used for accurate measurement of temperature. [SEMATECH]
thermography, infrared n		the process of displaying variations of apparent temperature (variations of temperature or emissivity, or both) over the surface of an object or a scene by measuring variations in infrared radiance. [ASTM E1316-94]
thermosonic bonding (T/S) n		a packaging bonding process that uses a combination of thermocompression bonding and ultrasonic energy bonding. [SEMATECH]
thick film n		a package layer deposited by screen printing and fired at high temperatures in order to fuse it into final form. [SEMATECH] Also see thick film metallization.
thick film metallization n		metallization that is deposited onto a ceramic substrate or layer by a screen printing process to achieve a layer of metal usually, by industry standards, in the 0.0003 to 0.001-in. thickness range. [SEMI G33-90]
thickness n		1 : of an epitaxial layer, the distance from the surface of the wafer to the layer-substrate interface. [SEMI M2-94 and ASTM F1241] 2 : of a semiconductor wafer, the distance through the wafer between corresponding points on the front and back surfaces. [ASTM F1241]
thickness variation n		in flat panel display substrates, any differences between maximum and minimum values within the thickness of a glass substrate. [SEMI D9-94] Also see total thickness variation.
thin film n		a specific class of either conducting or insulating film deposited onto a wafer surface. [SEMATECH]
thin film packaging n		a packaging method in which the conductors or insulators, or both are fabricated by means of deposition and patterning techniques. [SEMATECH]
three-ported two-way valve n		a type of shutoff valve of the basic two-way design, having either a single inlet port and two interconnected outlet ports or two interconnected inlet ports and a single outlet port. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
three-way valve n		a type of shutoff valve having two extreme positions, each of which either (1) directs an incoming single-gas stream to one of two alternate outlet ports, or (2) directs two different incoming gas streams alternately to a single outlet port. Some designs of three-way valves incorporate a position in which all ports are closed to flow. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
threshold n		a level set within the control software of a measurement instrument such that a signal that exceeds this level is recorded as an event and a signal below this level is ignored. [SEMATECH]
threshold adjustment n		an ion implant of approximately 1 x /cm2 using, for example, phosphorus, arsenic, or boron to controllably increase or decrease the threshold voltage of a metal oxide semiconductor transistor. [SEMATECH]
threshold limit value (TLV) n		the American Conference of Governmental Industrial Hygienists (ACGIH) guideline for the airborne concentration of a material to which nearly all U.S. workers can be exposed day after day without adverse effect. [SEMATECH]
throughput n		the number of wafers per hour through a machine, assuming 100% equipment uptime and a fully loaded machine. The number is adjusted downward for any detracting factors one wants to consider (for example, downtime, setup time, idle time, etc.) [SEMATECH]

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