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Topic: P type semiconductor

	Semiconductor - Wikipedia, the free encyclopedia
		A semiconductor is a material with electrical conductivity that is intermediate between that of an insulator and a conductor.
		Semiconductors may be elemental materials, such as silicon, compound semiconductors such as gallium arsenide, or alloys, such as silicon germanium or aluminium gallium arsenide.
		The ease with which electrons in a semiconductor can be excited from the valence band to the conduction band depends on the band gap between the bands, and it is the size of this energy bandgap that serves as an arbitrary dividing line between semiconductors and insulators.
	en.wikipedia.org /wiki/Semiconductors (2370 words)

	Semiconductor device and a process for producing same - Patent 6756280
		7 is a pattern diagram of the semiconductor device having the planar junction type diode using the vertical npn bipolar transistor according to an embodiment of the invention.
		In the n type epitaxial layer 102, a p type emitter region 101 is constructed, and a collector region 104 is constructed on the both ends thereof.
		Furthermore, in the planar junction type diode using the horizontal pnp bipolar transistor, a bias voltage Vf is supplied to the emitter electrode 170 corresponding to an anode, and the collector electrode 172c and the base electrode 172b corresponding to a cathode are commonly connected and connected to an outer circuit.
	www.freepatentsonline.com /6756280.html (5844 words)

	Semiconductor device and manufacturing method thereof patent invention (Site not responding. Last check: 2007-10-30)
		The p type well 3 is formed by the ion implantation of a p type impurity such as boron (B), and the n type well 4 is formed by the ion implantation of an n type impurity such as phosphorus (P) or arsenic (As).
		Then, a p type impurity such as boron (B) is ion-implanted into the regions on both sides of the gate electrode 11b of the n type well 4 to form (a pair of) p.sup.- type semiconductor regions 13 aligned with the gate electrode 11b of the n type well 4.
		The impurity concentration of the n.sup.+ type semiconductor region 15 is higher than that of the n.sup.- type semiconductor region 12, and the impurity concentration of the p.sup.+ type semiconductor region 16 is higher than that of the p.sup.- type semiconductor region 13.
	www.freshpatents.com /Semiconductor-device-and-manufacturing-method-thereof-dt20051229ptan20050285206.php?type=description (8681 words)

	Semiconductor - MSN Encarta
		The common semiconductors include chemical elements and compounds such as silicon, germanium, selenium, gallium arsenide, zinc selenide, and lead telluride.
		In a pure, or intrinsic, semiconductor such as silicon, the valence electrons, or outer electrons, of an atom are paired and shared between atoms to make a covalent bond that holds the crystal together (see Chemical Reaction; Crystal).
		When p-type and n-type semiconductor regions are adjacent to each other, they form a semiconductor diode, and the region of contact is called a p-n junction.
	encarta.msn.com /encyclopedia_761578100/Semiconductor.html (654 words)

	Semiconductor device - Patent 4001873
		In order to form P type region 12, the insulating film 16 may be first applied to the upper main face of the N type substrate 10 in its entirety and then provided at a predetermined portion with the window.
		2 was produced by preparing a P type silicon substrate 10 having a resistivity of from 10 to 20 ohms-centimeter and depositing in an atmosphere of hydrogen (H.sub.2) a polycrystalline silicon film 30 to a thickness of 900A upon a crystallographic plane (100) of the substrate 10 through the pyrolysis of monosilane (SiH.sub.4).
		The arrangement illustrated comprises a substrate 10 of N type silicon having a resistivity of from 30 to 40 ohms-centimeter and a P.sup.+ type semiconductor region 12 disposed in the substrate 10 in the manner as above described in conjunction with FIG.
	www.freepatentsonline.com /4001873.html (3185 words)

	N-type semiconductor - Wikipedia, the free encyclopedia
		An N-type semiconductor is obtained by carrying out a process of doping, that is, by adding an impurity of valence-five elements to the semiconductor in order to increase the number of free (in this case negative) charge carriers.
		This type of doping agent is also known as donor material since it gives away some of its electrons.
		Note that each movable electron within the semiconductor is never far from an immobile positive dopant ion, and the N-doped material normally has a net electric charge of zero.
	en.wikipedia.org /wiki/N-type_semiconductor (323 words)

	Semiconductor Primer
		Semiconductors doped in this way have a surplus of free electrons, or negative charge carriers, available to carry current and are consequently called N type materials.
		In P type materials the holes are said to be the majority carriers and electrons the minority carriers.
		Furthermore, the actual mechanisms involved in the functioning of semiconductor devices are much more complex and are based on quantum physics taking into account the energy levels of the charge carriers and their concentrations and distributions within the semiconductor crystal lattice.
	www.mpoweruk.com /semiconductors.htm (5304 words)

	HighBeam Encyclopedia â“ Free Online Encyclopedia for Reference, Research, Facts
		The transistor is an arrangement of semiconductor materials that share common physical boundaries.
		The p-n-p junction transistor, consisting of a thin layer of n -type semiconductor lying between two p -type semiconductors, works in the same manner, except that all polarities are reversed.
		The metal-oxide semiconductor field-effect transistor (MOSFET) is a variant in which a single gate is separated from the channel by a layer of metal oxide, which acts as an insulator, or dielectric.
	www.encyclopedia.com /printable.aspx?id=1E1:transist (556 words)

	Transistors
		A transistor is simply a triode - either an n type semiconductor sandwiched between two p type semiconductors, as in the figure below, or a p type semiconductor sandwiched between two n type semiconductors.
		As in the diode, as electric field is established in a certain direction in the vicinity of the junctions between the two types of semiconductors.
		In a transistor, a current flowing from the emitter to the collector is greatly affected by the bias of these electric fields, and these fields are controlled by a signal fed into the base.
	theory.uwinnipeg.ca /mod_tech/node173.html (235 words)

	P-type semiconductor (Site not responding. Last check: 2007-10-30)
		A semiconductor type in which the density of electrons in the conduction band is exceeded by the density of holes in the valence band.
		P-type behavior is induced by the addition of acceptor impurities, such as boron, to the crystal structure of silicon.
		In P-type semiconductors, holes are the majority carriers, and electrons are the minority carriers.
	encyclobeamia.solarbotics.net /articles/p_type.html (57 words)

	Semiconductor Primer, semiconductors 101
		The unique physical properties of certain materials we now recognise as semiconductors have been known for over a hundred years but it was only in the 1940's that materials were classified as such and their properties were explained.
		However, when a single crystal is doped in the form of a junction, with N type material on one side and P type material on the other side the electrons are attracted by the holes on the other side of the junction and migrate across to bond with them.
		The central N type layer is only slightly doped and is also thicker than the other layers enabling it to support a high blocking voltage.
	www.mpoweruk.com /semis.htm (5947 words)

	Transene - Semiconductor Materials
		Semiconductor grade phosphorus, arsenic, antimony and boron diffusants for semiconductor devices.
		Transene diffusants are hyper-pure semiconductor grade chemicals, dispensed in convenient unit quantities for solid state diffusion processes.
		N- and P- Diffusol preparations may be diluted when lower surface concentration of diffusants is desired.
	www.transene.com /diffusant.html (701 words)

	semiconductor - a definition from Whatis.com
		A semiconductor is a substance, usually a solid chemical element or compound, that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current.
		An N-type semiconductor carries current mainly in the form of negatively-charged electrons, in a manner similar to the conduction of current in a wire.
		In a semiconductor material, the flow of holes occurs in a direction opposite to the flow of electrons.
	whatis.techtarget.com /definition/0,,sid9_gci212960,00.html (317 words)

	P-type semiconductor - Free net encyclopedia (Site not responding. Last check: 2007-10-30)
		A P-type semiconductor is obtained by carrying out a process of doping, that is adding a certain type of atoms to the semiconductor in order to increase the number of free (in this case positive) charge carriers.
		This type of doping agent is also known as acceptor material and the semiconductor atoms that have lost an electron are known as holes.
		Each hole is associated with a nearby negative-charged dopant ion, and the semiconductor remains electrically neutral as a whole.
	www.netipedia.com /index.php/P-type_semiconductor (310 words)

	PHYS 313 - Semiconductor Physics and Devices
		Semiconductors exhibit relatively high resistance in a pure state and much lower resistance when they contain small amounts of certain impurities.
		A diode is a two-terminal semiconductor device that exhibits a non-linear current-voltage characteristic.
		There are two kinds of semiconductor diodes: a P-N junction diode, which forms an electrical barrier at the interface between N- and P-type semiconductor layers, and a Schottky diode, whose barrier is formed between metal and semiconductor regions.
	home.ku.edu.tr /~aserpenguzel/phys313.html (1470 words)

	[No title]
		Perhaps the first to apply semiconductor diodes to the radio art was the remarkable Jagadis Chandra Bose, who applied for a patent on a galena detector in 1901 (it was finally awarded in 1904).
		The interesting property of a semiconductor is that thermally excited electrons can move from the valence band to the conduction band and conduct current.
		In N-type semiconductors the majority of free charge carriers are negative, while in a P-type semiconductor the majority are positive.
	www.geocities.com /omkkl/pod.html (2057 words)

	semiconductor from FOLDOC (Site not responding. Last check: 2007-10-30)
		Semiconductors are used to make diodes, transistors and other basic "solid state" electronic components.
		Where n and p type regions adjoin, a junction is formed which will pass current in one direction (from p to n) but not the other, giving a diode.
		One model of semiconductor behaviour describes the doping elements as having either free electrons or holes dangling at the points in the crystal lattice where the doping elements replace one of the atoms of the foundation material.
	www.instantweb.com /foldoc/foldoc.cgi?query=semiconductor&action=Search (242 words)

	How Things Work - Audio Amplifiers
		Doped semiconductor containing mobile negative charges is called "n-type" and that with mobile positive charges is called "p-type." In a bipolar transistor, the two outer layers of the sandwich are of the same type and the middle layer is of the opposite type.
		Whenever current is flowing through a diode, electrons are moving from the n-type semiconductor on one side of the diode's p-n junction to the p-type semiconductor on the other side of the junction.
		In this device, three layers of semiconductors are sandwiched together: an n-type piece (the source), a long, thin p-type piece (the channel), and another n-type piece (the drain).
	rabi.phys.virginia.edu /HTW/audio_amplifiers.html (7841 words)

	Semiconductor device patent invention (Site not responding. Last check: 2007-10-30)
		The diffusion region 105 is formed at the surface of the epitaxial layer 103 by impurity diffusion.
		[0016] For example, the thickness of the epitaxial layer 103 between the semiconductor substrate 102 and the diffusion region 105, 123 depends on the diffusion depth of the diffusion region 105, 123.
		Therefore, it is difficult to properly keep the charge balance among the semiconductor substrate 102, the epitaxial layer 103 and the diffusion region 105, 123.
	freshpatents.com /Semiconductor-device-dt20050519ptan20050104124.php (1390 words)

	SILICON STRIP DETECTORS, PERFORMANCE CHARACTERISTIICS Stuart Briber, Research Experience for Teachers participant 8/99
		This in turn is surrounded by a closed ring of P+ type doped semiconductor, approximately 20 microns in width and overlain by a trace of aluminum, called the guard ring (Fig.
		It is the result of internal currents inside the chip as electrons and holes are redistributed inside the semiconductor in creating the depletion zone (region inside the bulk of the semiconductor wafer which is devoid of free charge carriers).
		This is the process whereby the applied voltage sweeps the electrons from the N- doped bulk into the positive holes of the dopant atoms in the P+ type semiconductor thereby establishing an internal electric field opposing the external field.
	scipp.ucsc.edu /program/ret/99/stuartreport.html (2158 words)

	Semiconductor device
		The development of radar during World War II did much to revive the fortunes of crystal detectors (and, as a result, that of semiconductor devices) -- although temperamental, crystals were better than vacuum-tube diodes at rectifying the high frequencies used by radar.
		Depending on the selection of impurities (often called dopants) added, semiconductor material of two electrically-different types can be created -- one that is electron-rich (called N-type, where N stands for Negative), or one that is electron-poor (called P-type, where P stands for Positive).
		Most of the "magic" of semiconductor devices occurs at the boundary between P-type and N-type semiconductor material -- such a boundary is called a P-N junction.
	encyclobeamia.solarbotics.net /articles/semiconductor_dev.html (375 words)

	The Chip Collection - Chip Talk - Historical - Smithsonian Institution
		A region of surface conduction opposite in type from that of the bulk doping of an FET transistor.
		A type of semiconductor memory in which the presence or absence of a capacitive charge represents the state of a binary storage element.
		The boundary between a P region and an N region in a semiconductor substrate.
	smithsonianchips.si.edu /chiptalk/vocab.htm (2035 words)

	C&EN: TODAY'S HEADLINES - SEMICONDUCTOR SWITCHEROO
		Because organic-based semiconductors can be made smaller and are more flexible than silicon-based materials, they are expected to lie at the heart of future generations of thin-film transistors, light-emitting diodes, and other electronic devices.
		The oligomers with perfluoroarenes in the inner positions of the chain are p-type semiconductors, they found--the same as sexithiophene.
		Marks and coworkers attribute the differences in electronic behavior "to a subtle interplay of molecular stereoelectronic effects on molecular energy levels." These effects are modulated by differences in intermolecular packing of the oligomers that result from interactions between the electron-poor perfluoroarene rings and electron-rich thiophene rings, they note.
	pubs.acs.org /cen/topstory/8135/8135notw8.html (384 words)

	Introduction to Themoelectric Cooling KeyWords:(Thermoelectric Cooler TEC Peltier)
		The elements of semiconductor material are connected electrically in series and thermally in parallel.
		When a positive DC voltage is applied to the n-type thermoelement, electrons pass from the p- to the n-type thermoelement and the cold side temperature will decrease as heat is absorbed.
		With these principles in mind and the introduction of semiconductor materials in the late 1950's, thermoelectric cooling has become a viable technology for small cooling applications.
	www.marlow.com /TechnicalInfo/introduction_to_themoelectric_co.htm (327 words)

	What is a semiconductor? by Elmer Epistola - www.SiliconFarEast.com
		The conductivity of a semiconductor increases with temperature, light, or the addition of impurities because these increase the number of conductive valence electrons of the semiconductor.
		In an intrinsic semiconductor such as silicon, the valence electrons of an atom are paired and shared with other atoms, making covalent bonds that hold the crystal together.
		In n- type silicon, donor atoms such as phosphorus (P), with five valence electrons, replace some silicon and provide extra negative electrons.
	www.siliconfareast.com /whatissemicon.htm (375 words)

	Dr. Viktor Chikan (Site not responding. Last check: 2007-10-30)
		First, the physical properties of the semiconductor material can be engineered by changing the size in the nanometer size regime, where the Bohr radius of an exciton is comparable to the spatial extent of the particle.
		The third way of controlling the physical properties of a semiconductor material is doping, by substituting a few atoms in the crystal structure with different elements.
		If the dopant is electronically different from the replaced atom, the carrier concentration may change, resulting in a p- or n-type semiconductor quantum dot.
	www.k-state.edu /chem/personnel/faculty/grad/vc/chikan.html (780 words)

	semiconductor-course
		Another common transistor, the bipolar transistor, is formed by sandwiching a thin layer of P- or N-type semiconductor between two regions of the opposite type of semiconductor.
		Semiconductor devices (e.g., transistors), are made by introducing controlled amounts of impurity atoms into a semiconducting crystal.
		Semiconductor regions with an excess of positive charges are called "P-type" regions (Meindl, 1977, 1987).
	bmrc.berkeley.edu /courseware/ICMfg92 (8244 words)

	Pharmacom Glossaries
		Bipolar Junction Transistor; a transistor in which current is controlled by the voltage impressed across a crystal interface between p and n type semiconductor.
		Complementary Metal-Oxide-Semiconductor; a process technology which is capable of producing MOS transistors with both n and p type semiconductor conducting channels.
		Gallium Arsenide; a semiconductor crystal which is a compound of the elements gallium and arsenic.
	www.pharmacom.us /pharmacom.glossaries.microelectronics.html (1756 words)

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