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

"H"

handler n		equipment for manipulating packaged integrated circuits during the testing process. [1994 National Technology Roadmap for Semiconductors]
hand scribe mark n		in the manufacture of silicon wafers, any marking, usually on the back surface of a wafer, scratched manually into the silicon surface, as with a diamond tipped scribe, for purposes of wafer identification. [SEMI M8-93]
hard bake n		heat treatment of a wafer after develop to fully harden the resist prior to etch. [SEMATECH] Also see post-exposure bake.
hardware safety n		a circuit of electromechanical components, wiring, or light links that override associated programmed machine controls. When the circuit is interrupted, final control elements are not allowed to operate. [SEMI S2-93]
hardware/software co-design n		a style of system design that considers whether specific system functions should be realized as software or as hardware, by analyzing trade-offs between design alternatives. [1994 National Technology Roadmap for Semiconductors]
hardwired interlock n		an electromechanical connection through which interlock conditions are verified. [SEMATECH]
hazard n		a set of recognizable conditions with the potential for initiating an event that could result in death, injury, or illness to people, and/or facility/equipment damage. [SEMI S1-90]

hazardous gases n		gases supplied in cylinders that are listed in National Fire Protection Association (NFPA) 49 with a degree of hazard rating 3 or 4 in Health, Flammability, or Reactivity, or which would be so rated by experienced, technically competent persons when evaluated in accordance with the criteria set forth in NFPA 704. [SEMI S5-93]
hazardous materials n		1 : those chemicals or substances that are physical hazards or health hazards as defined and classified in National Fire Protection Association (NFPA) 704, whether the materials are in use or in waste conditions. [SEMI S2-93] 2 : substances or mixtures having properties capable of producing adverse effects on the health or safety of a human. [SEMATECH]
hazardous production materials (HPM) n		1 : the chemicals and specialty gases used in processing wafers. [SEMATECH] 2 : a solid, liquid, or gas that has a degree-of-hazard rating in health, flammability, or reactivity of Class 3 or 4 as ranked by Uniform Fire Code (UFC) Standard No. 79-3 and that is used directly in research, laboratory, or production processes with nonhazardous end products. (1988 Uniform Fire Code, Section 51.102) [SEMI F13-92]
hazardous voltage n		see National Electric Code (NEC) hazardous voltage.
HAZCOM n		1 : an online VAX computer material safety data sheet (MSDS) inventory maintained to comply with requirements of the Occupational Safety and Health Administration (OSHA) Hazard Communication Standard. Using HAZCOM allows anyone on site to access MSDS and other personal chemical safety information. [SEMATECH] 2 : the Hazard Communication Standard, a piece of legislation that requires chemical manufacturers and importers to assess the hazards associated with the materials in their workplace and to inform workers of those hazards. [SEMATECH]
haze n		on a semiconductor wafer, nonlocalized light scattering resulting from surface topography (microroughness) or from dense concentrations of surface or near-surface imperfections. [ASTM F1241] Also see laser-scattering light event. .
H-bar n		see crossbar.
header n		in SECS-I, a 10-byte data element used by the message and transaction protocols. NOTE-The header is contained in each block of a message. The operation of all communications functions above the block transfer protocol is linked to information in the header. [SEMI E4-91]
health hazards n		a classification of a chemical for which there is statistically significant evidence, based on at least one study that was conducted in accordance with established scientific principles, that acute or chronic health effects may occur in exposed persons. (See Occupational Safety and Health Administration Regulations, 29 CFR 1910.1200.) [SEMI S2-93] Also see other health hazard.
heat exchanger n		a module or piece of equipment used to transfer heat from one medium to another without contact between the media, such as from a chemical bath to a chiller. [SEMATECH]
heat exchange area n		in cofired ceramic packages, a metallized region on one major surface of the package to which heat sinks may be attached by brazing, soldering, or adhesive resin. [SEMI G61-94]
heat sink n		a heat-conductive metal form attached to a device package to transmit heat away from the source. [SEMATECH]
heat trace n		heating of a component, spool piece, or test stand by a uniform and complete wrapping of the item with resistant heat tape. [SEMATECH]
heavy ion backscattering n		an analytical technique similar to Rutherford backscattering but which uses heavy ions as the probe. [SEMATECH] t
helium (He) n		a rare gas or cryogenic liquid that is inert, colorless, odorless, and tasteless. Helium is used as an inert gas in systems for purging, blanketing, and pressurizing and as a carrier gas. It also is used as a substitute for argon in many plasma and annealing processes. [SEMI C3.20-85]
helium leak rate n		the rate of helium leakage into or out of a gas system, component, fitting, or vessel. The helium leak rate is expressed in standard cubic centimeters per second. [SEMI International Standards 1990, Vol. 1, Glossary]
helium mass spectrometer leak detector n		an analytical instrument designed to detect leakage of helium into or out of a gas system. [SEMI International Standards 1990, Vol. 1, Glossary]
HEPA n		see high-efficiency particulate air (HEPA) filter.
hermetic seal n		a coat applied in the final stage of thermal processing to seal the ceramic package and to protect the device from the external environment. [SEMATECH]
hertz (Hz) n		a term applied to the number of repetitions of a periodic wave per second. [SEMATECH]
heteroepitaxy n		a type of epitaxy in which a single-crystal layer is grown on a substrate of different material that has a compatible crystal structure. [SEMATECH] Contrast homoepitaxy.
heterogeneous environment n		an environment that contains a collection of platforms having both similar and significantly different parts. [SEMATECH]
heuristic adj		pertaining to exploratory methods of problem solving in which solutions are discovered by evaluation of the progress made toward the end result. [SEMATECH] Contrast algorithmic.
hexachlorobutadiene (C4Cl6)		a poisonous, possibly carcinogenic gas present in plasma aluminum etchers. [SEMATECH] Also see dry plasma etch.
hexachloroethane (C2Cl6) n		a poisonous, possibly carcinogenic gas present in plasma aluminum etchers. [SEMATECH] Also see dry plasma etch.
hexafluoroethane (C2F6) n		a chemical compound; one of the most stable of all organic compounds. It is inert, colorless, nonflammable, odorless, and tasteless. Hexafluoroethane is used as a plasma etchant and in the cleaning of deposition equipment. [SEMI C3.25-85]
hexamethyldisilazane (HMDS) n		a chemical compound used as a preresist wafer treatment to improve adhesion of resist to wafers. [SEMATECH]
hexode n		a six-electrode electron tube containing an anode, a cathode, a control electrode, and three additional electrodes that, ordinarily, are grids. (Copyright 1993 IEEE. All rights reserved.)
hierarchical design n		concurrent, incremental design. [1994 National Technology Roadmap for Semiconductors] See design process.
hierarchical design methodology n		see self-consistent top-down design.
high-current implanter n		a subtype of ion implanters which is typified by beam currents in excess of 3 mA and by the use of batch processing. [SEMATECH]
high-efficiency particulate air (HEPA) filter n		a replaceable extended media, dry-type filter in a rigid frame and having a minimum particle-collection efficiency of 99.97% on all particles larger than 0.3 micrometer. [SEMATECH]
highly oriented pyrolytic graphite (HOPG) n		a type of pure, highly laminar graphite used as an atomic-scale calibration standard for atomic force microscopy and scanning tunneling microscopy. [SEMATECH]
highly toxic gas n		a chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each. [SEMI F6-92]
highly toxic material n		material that produces a lethal dose or lethal concentration that falls within any of the following categories: a chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each a chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each a chemical that has a median lethal concentration (LC50) in the air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each material that produces a lethal dose or lethal concentration that falls within any of the following categories: Mixtures of these materials with such ordinary materials as water may not warrant a highly toxic classification. While this system is basically simple in application, any hazard evaluation that is required for the precise categorization of this type of material should be performed by experienced, technically competent persons. [SEMI S2-93]
high-pressure isolation (HPI) valve n		a shutoff valve located on the high-pressure side of a gas piping system that, when closed, isolates the purged volume from the pressure regulator and other downstream components. [SEMI F13-93]
high-pressure purge system n		a purge system in which the purged volume is entirely on the high-pressure side of the gas system. The two valves required are a purge gas inlet valve and a high-pressure vent valve. [SEMI International Standards 1990, Vol. 1, Glossary]
high-pressure side n		of a gas piping system, all piping and components upstream of the pressure regulator, and in which the contained gas is at the same pressure as the gas cylinder or source. The high-pressure side includes the inlet chamber of the pressure regulator, as well as the cylinder pressure gauge. The term "high pressure" in this instance does not imply a particular value of pressure. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
high-pressure vent (HPV) valve n		a shutoff valve located on the high pressure side of a gas piping system that controls the release of gas from the system. [SEMI Chemicals/Gases, Vol. 1, 1990 (no longer in print)]
high voltage n		see National Electric Code (NEC) high voltage.
hillock n		a defect caused by stress that raises portions of a metal (such as aluminum) film above the surface of the film. Localized stress within the metal film may elevate portions of the film through the adjacent dielectric layer, resulting in a metal extrusion and a short to the next metal layer. [SEMATECH] Also see pyramid.
histogram n		a graph obtained by dividing the range of the data set into equal intervals and plotting the number of data points in each interval. [EIA 557]
HMDS n		see hexamethyldisilazane.
hold-down latch n		a mechanism for locking the box to the port plate. [SEMI E19.4-94]
hole n		1 : of a semiconductor, a mobile vacancy in the electronic valence structure that acts like a positive electron charge with positive mass; the majority carrier in p-type material. [SEMI M1-94 and ASTM F1241] 2 : in plastic and metal wafer carriers, the area through which a pin from another wafer carrier can enter for the transfer of wafers. [SEMI E1-86]
homoepitaxy n		a type of epitaxy in which a single-crystal layer is grown on a substrate of the same material. [SEMATECH] Contrast heteroepitaxy.
HOPG n		see highly oriented pyrolytic graphite.
horizontal furnace n		a family of furnaces in which the wafers are loaded and processed in a horizontal tube. [SEMATECH]
horizontal orientation n		see wafers, horizontal.
host n		in automated material movement, the intelligent system that communicates with the equipment. [SEMI E32-94]
hot-carrier diode		see Schottky barrier diodes.
hot carriers n		those carriers, which may be either electrons or holes, that have been accelerated by the large traverse electric field between the source and the drain regions of a metal oxide semiconductor field-effect transistor (MOSFET). They can jeopardize the reliability of a semiconductor device when these carriers are scattered (that is, deflected) by phonons, ionized donors or acceptors, or other carriers. The scattering phenomenon can manifest itself as substrate current, gate current, or trapped charges. [SEMATECH]
hot lot n		a high-priority wafer lot. [SEMATECH]
HPM n		see hazardous production materials.
hydrobromic acid (HBr) n		an acid that is useful for dissolving solders. [SEMATECH]
hydrochloric acid (HCl) n		a poisonous solution of hydrogen chloride gas in water. This acid is pungent and highly corrosive. [SEMATECH]
hydrofluoric acid (HF) n		a poisonous solution of hydrogen fluoride gas in water. This colorless, fuming liquid is extremely corrosive and will etch glass. Hydrofluoric acid is used to etch silicon dioxide and, when combined with other acids, silicon. [SEMATECH]
hydrogen (H2) n		the lightest known gas; hydrogen vapors are highly flammable, colorless, odorless, tasteless, and nontoxic. Hydrogen is used as a means of providing a reducing atmosphere, as a carrier gas for epitaxial processes, and as a reagent to produce high-purity water. It sometimes is used in gas mixtures of fluorine-based plasma etchant for the processing of silicon dioxide film. [SEMI C3.4-88] Also see dry plasma etch.
hydrogen chloride (HCl) n		a colorless, pungent, corrosive gas having a suffocating odor. It is heavier than air and fumes strongly in moist air. Hydrogen chloride is very soluble in water and alcohol and less soluble in ether. In semiconductor processing, hydrogen chloride is used in such processes as etching, oxidation, passivation, and epitaxy. It also is used as a plasma and reactive ion etch of silicon and polysilicon, as well as aluminum metallization. [SEMI C3.3-88]
hydrogen peroxide (H2O2) n		1 : a colorless, unstable compound, soluble in water and alcohol. [SEMI C1.9-90] 2 : a compound used as a catalyst in many etch formulations, such as piranha. [SEMATECH]
hydrophilic adj		having a strong affinity for water; wettable. [ASTM F1241]
hydrophobic adj		having little affinity for water; nonwettable. [ASTM F1241]
hypoxia n		an abnormal deficiency of oxygen in the blood or tissues. [SEMATECH]
hysteresis n		in regulator performance testing, the pressure difference between readings, taken as flow is increased from a prescribed minimum to a prescribed maximum, and the pressure as the flow is decreased back to the prescribed minimum. The hysteresis curve represents the major loop developed over the entire operating range of the regulator, while the operating hysteresis value is calculated from a minor loop, developed over a limited flow range. [SEMATECH]

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