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Topic: Avalanche breakdown

	Semiconductor device having a high breakdown voltage junction characteristic - Patent 4153904
		The concept of avalanche breakdown, and the operation of the invention to increase the bias voltage at which avalanche breakdown occurs, is best understood by considering the dynamics of the mobile and immobile charge carriers at the junction under several different bias voltage conditions.
		However, the reverse bias voltage which causes avalanche breakdown in the disclosed structure is substantially, greater than the reverse bias breakdown voltage for conventional structures which have no second doped region 30.
		4; and the avalanche breakdown voltage is accordingly increased.
	www.freepatentsonline.com /4153904.html (5232 words)

	breakdown
		Breakdown is characterized by the rapid increase of the current under reverse bias.
		The breakdown voltage is a key parameter of high power devices but also for logic devices as one typically reduces the device dimensions without reducing the applied voltages, thereby increasing the internal electric field.
		Avalanche breakdown is caused by impact ionization of electron-hole pairs by carriers that have gained energy by accelerating in the high electric field in the depletion region of a reversed biased p-n diode.
	ece-www.colorado.edu /~bart/book/breakdown.htm (831 words)

	Avalanche breakdown - Wikipedia, the free encyclopedia
		Avalanche breakdown is a phenomenon that can occur in both insulating and semiconducting materials.
		The electric field strength necessary to achieve avalanche breakdown varies greatly between different materials: in air, 3 MV/m is typical, while in a good insulator such as some ceramics, fields in excess of 40 MV/m can be needed.
		In devices that exploit the avalanche effect, the electric field is normally kept just below the threshold at which avalanche breakdown is possible, resulting in a current that is highly dependent on the generation of free electrons.
	en.wikipedia.org /wiki/Avalanche_breakdown (653 words)

	Raportti Optekno-projektiin
		The avalanche breakdown does not cause permanent damages, but in the secondary breakdown a local channel is created between the collector and the emitter and the temperature in the channel may rise so high that the semiconductor material melts.
		When an avalanche transistor is used as a switch, as shown in figure 1, a leakage current MI flows from the collector to the base in the off-state, where M is the avalanche multiplication of the leakage current between the collector and the base.
		For this reason the avalanche multiplication factor M and the voltage BV needed to hold on the avalanche process are smaller than in the case of avalanche breakdown between collector and base with open emitter (BV), in which case no electrons come from the emitter.
	www.ee.oulu.fi /~arik/pulse.htm (4064 words)

	Reverse bias breakdown
		The breakdown of logic devices is equally important as one typically reduces the device dimensions without reducing the applied voltages, thereby increasing the internal electric field.
		Breakdown voltage and depletion layer width at breakdown versus doping density of an abrupt one-sided p-n diode.
		Avalanche breakdown is caused by impact ionization of electron-hole pairs.
	ece-www.colorado.edu /~bart/book/book/chapter4/ch4_5.htm (699 words)

	Elimination of radius of curvature effects of p-n junction avalanche breakdown using slots - Patent 5912501
		The mechanism of avalanche breakdown in a pn junction limits the maximum reverse-bias voltages that can be applied to a pn junction and is also responsible for some of the maximum operating voltage values in bipolar transistors.
		The breakdown of the CB junction with I.sub.E =0 (BV.sub.CBO) is due to this mechanism.
		The breakdown voltage is plotted versus impurity concentration for selected radii of curvature, r.sub.j, from 0.1 micron to 10 microns and a plot of no curvature (r.sub.j =.infin.).
	www.freepatentsonline.com /5912501.html (4505 words)

	Avalanche Safety -- Recommendations and Resources (Site not responding. Last check: 2007-10-21)
		For other uses, see Avalanche (disambiguation)'' An avalanche is caused when a build up of snow is released down a slope, and is one of the major dangers faced in the mountains in winter.
		Avalanches are often classified by what they are made of, for example snow, ice, rock or soil avalanches.
		Avalanches occur when the load on the upper snow layers exceeds bonding forces (bonding to layer beneath, support from anchors such as rocks and trees, stress support from top or bottom of slope).
	www.becomingapediatrician.com /health/9/avalanche-safety.html (1373 words)

	Text of MIJ-NSR Volume 2, Article 11 (Site not responding. Last check: 2007-10-21)
		Avalanche breakdown luminescence in GaN was studied previously in cases of i-n- and MIS - diodes [6] [7] [8] [9].
		It was shown that at reverse bias, electrons are tunneling from metal to the n-side of the junction and at sufficiently high voltage cause impact ionization and avalanche breakdown.
		The intensity of the breakdown luminescence is 6-7 orders of magnitude lower than of the injection ones, as indicated on the ordinate axes.
	nsr.mij.mrs.org /2/11/text.html (1295 words)

	Nanotechnology at Zyvex
		This rush is termed “avalanche breakdown,” which is a runaway process resulting in a current spike.
		Its counterpart, dielectric strength, indicates the relationship between thickness and breakdown voltage, and is expressed as a ratio of voltage to thickness.
		Breakdown of a 50 micron by 2 micron polysilicon-filled nitride isolation trench on a silicon-based MEMS device.
	www.zyvex.com /Products/MEBD_001a.htm (2273 words)

	Random Electrical Noise: A Literature Survey
		Avalanche breakdown occurs when the acceleration of carriers in the space-charge region is great enough to cause ionizing collisions with atoms, thus producing mobile hole-electron pairs.
		Zener breakdown is the direct disruption of covalent bonds by the electric field force, and does not require acceleration of a primary carrier by the field.
		In such diodes the breakdown current is produced by the Zener mechanism; the electric field is very high, and the space-charge layer is so thin that carriers spend too little time in the space-charge layer to produce significant numbers of secondary carrier pairs.
	www.ciphersbyritter.com /RES/NOISE.HTM (8483 words)

	NCSR - Avalanche Diode
		If the device has a designed breakdown voltage for which it is intended to be used it is called either a zener diode, breakdown diode, or an avalanche diode.
		Common uses of breakdown diodes include, voltage regulators where the voltage is required to be a constant regardless of the current drawn.
		A somewhat typical avalanche diode will have a specified breakdown voltage the example below is for a 7V breakdown, the breakdown equation below is somewhat contrived, but illustrates the idea of avalanche breakdown.
	www.onr.navy.mil /sci_tech/31/312/ncsr/devices/avalanche.asp (212 words)

	Avalanche Awareness: Information About Avalanches and Avalanche Safety
		According to the Colorado Avalanche Information Center, 89 percent of victims are men, most victims are between the ages of 20-29 (although the average victim age is 31), and three-quarters of victims are experienced backcountry recreationists (who are more likely to enter risky situations).
		All that is necessary for an avalanche is a mass of snow and a slope for it to slide down.
		Avalanches can fall in a "piecemeal" fashion, where one avalanche will run and leave the rest of the slope weakened, and the slightest provocation can cause subsequent avalanches on that same slope.
	nsidc.org /snow/avalanche (5120 words)

	SPECIAL DEVICES
		When the breakdown point of the PN junction is reached, large numbers of minority carriers "tunnel" across the junction to form the current that occurs at breakdown.
		The second theory of reverse breakdown effect in diodes is known as AVALANCHE breakdown and occurs at reverse voltages beyond 5 volts.
		The breakdown is at a higher voltage because of the higher resistivity of the material.
	www.tpub.com /neets/book7/26.htm (1819 words)

	Drift-free avalanche breakdown diode - US Patent 5691558 (Site not responding. Last check: 2007-10-21)
		An avalanche breakdown diode includes a p-doped trough in which a highly p-doped region is introduced.
		The conductive layer and the n-doped region are connected to a positive voltage and the highly p-doped region is connected to a negative voltage.
		In addition, the resistance during the breakdown is small due to the defined interspace between the trough and the layer.
	www.patentstorm.us /patents/5691558.html (309 words)

	Avalanche-enhanced CMOS transistor for EPROM/EEPROM and ESD-protection structures (US5719427) (Site not responding. Last check: 2007-10-21)
		Since the avalanche electrons are generated by the diode rather than by the programmable transistor itself, programming efficiency no longer depends on the channel length and other parameters of the programmable transistor.
		The breakdown voltage of the diode is adjusted by varying the lateral spacing between the n+ drain and the p+ diffusion.
		whereby the avalanche-generating diffusion in close proximity to the drain diffusion initiates avalanche breakdown when the critical reverse voltage bias is applied, and whereby avalanche breakdown occurs at a lower voltage in the avalanche-breakdown diode than in the channel of the avalanche-enhanced transistor.
	www.delphion.com /details?pn=US05719427__ (643 words)

	[No title] (Site not responding. Last check: 2007-10-21)
		The magnitude and duration of these pulses is sufficient to cause breakdown and heating of the lower ionosphere (80-95 km) and leads us to suggest that sprites may also launch the EMP responsible for the production of elves.
		For the avalanches to develop the intensity of the electric force eE should be over the relativistic minimum of electron energy losses per unit path L/sub min/ that exists in the vicinity of electron energy epsilon approximately=1 MeV.
		Formation of relativistic runaway electron avalanche initiated by cosmic-ray showers within the space domain of a thunderstorm electric field, is the heart of the theory.
	nova.stanford.edu /~vlf/bibliography/runaway.bib (2463 words)

	Zener and Avalanche Breakdown/Diodes
		"Avalanche breakdown is caused by impact ionization of electron-hole pairs.ÝWhile very little current flows under reverse bias conditions, some current does flow.ÝThe electric field in the depletion region of a diode can be very high.
		"Avalanche breakdown occurs in lightly-doped pn-junctions where the depletion region is comparatively long.ÝThe doping density controls the breakdown voltage.ÝThe temperature coefficient of the avalanche mechanism is positive.ÝThat is, as the temperature increases, so does the reverse breakdown voltage.ÝThe magnitude of the temperature coefficient also increases with increasing breakdown voltage.
		At low doping levels and higher voltages the avalanche mechanism dominates while at heavy doping levels and lower voltages the Zener mechanism dominates.ÝAt a certain doping level and around 6 V for Si, both mechanism are present with temperature coefficients that just cancel.
	people.deas.harvard.edu /~jones/es154/lectures/lecture_2/breakdown/breakdown.html (448 words)

	Avalanche photodiode - Wikipedia, the free encyclopedia
		Avalanche photodiodes (APDs) are photodetectors that can be regarded as the semiconductor analog to photomultipliers.
		Avalanche photodiodes therefore are more sensitive compared to other semiconductor photodiodes.
		Breakdown characteristics in InP/InGaAs avalanche photodiode with p-i-n multiplication layer structure, Hyun, Kyung-Sook; Park, Chan-Yong; Journal of Applied Physics, vol.
	en.wikipedia.org /wiki/Avalanche_photodiode (717 words)

	Reverse Biased/Breakdown (Site not responding. Last check: 2007-10-21)
		This process is called avalanche multiplication (figure 3), because we start with one carrier, and through a succession of impacts create more and more current.
		There is now a sudden onset of current after the avalanche breakdown voltage has been exceeded.
		Diodes in breakdown are used as voltage references (the voltage across them is more or less independent of the current running through them) but you will always find a series current limiting resistor used along with them.
	cnx.org /content/m1009/latest (530 words)

	The Unusual Diode FAQ - IV.14 - Zener Diodes
		The breakdown mechanism may be avalanche breakdown or Zener breakdown, or a mixture of the two.
		The temperature coefficient of the avalanche mechanism is positive, that is, at higher temperature, the avalanche breakdown voltage increases.
		The temperature coefficient of the tunneling breakdown is negative.
	www.avtechpulse.com /faq.html/IV.14 (613 words)

	WBG Microwave Device Research at Purdue (Site not responding. Last check: 2007-10-21)
		Because of its high breakdown field, silicon carbide is an ideal semiconductor for the fabrication of high-power microwave devices.
		Because of the difference in doping between the "drift region" and "avalanche region", the electric field is highly peaked in the avalanche region and nearly flat in the drift region.
		In operation, avalanche breakdown occurs at the point of highest electric field, and this generates a large number of hole-electron pairs by impact ionization.
	www.ecn.purdue.edu /WBG/Device_Research/IMPATT_Diodes/Index.html (760 words)

	Experiments - Experimental Measurements
		Most modern mosfets are designed to cope with a limited degree of avalanche breakdown through the D-S path, these are described as 'avalanche rugged' or 'avalanche rated' devices.
		The limiting factor governing this breakdown is the junction temperature rise due to energy dissipation.
		The avalanche breakdown capability is, however, still useful in a coilgun context.
	www.coilgun.eclipse.co.uk /mosfet_switching_results.html (1509 words)

	Electronic Products (Site not responding. Last check: 2007-10-21)
		The drain-source breakdown voltage (BV) of a power MOSFET has a positive temperature co-efficient, so as temperature rises, a higher voltage is required to cause breakdown.
		For practical purposes, breakdown voltage in real applications is calculated at 1.3 times the rated low-current breakdown voltage.
		The junction temperature rise caused by the avalanche breakdown must be added to the junction temperature during normal operation.
	www.electronicproducts.com /print.asp?ArticleURL=fairchild.mar2005.html (1284 words)

	OTL - File # 2114
		The floating ring region acts as a guard ring to prevent breakdown at the junction edge of the photodiode and is concentrically circling the central region at the top surface of the photodiode.
		The structure results in an enhanced avalanche effect in the central region with limited edge breakdown undesirable consequences.
		The avalanche effect is further enhanced in the central region by the alternative composition suggested in the patent.
	www.usc.edu /academe/otl/2114.htm (225 words)

	Re: Why the electrical arc has a negative dynamical resistence?
		Once the ions and the electrons that make up the plasma are created by the initial gas breakdown, the residual voltage is usually high enough to accelerate them (the ions to the negative electrode, the electrons to the position electrode) a lot.
		This progressive breakdown continues until the electrical source just can't supply enough energy to keep the process going, and the voltage drops to the point where there isn't enough acceleration to create more electrons and ions.
		While the general avalanche discharge process is the same in both, fluorescent lamps generally have ionization filling most of the tube volume in a diffuse glow discharge.
	www.madsci.org /posts/archives/jun2000/962111476.Ph.r.html (963 words)

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