EPE Association: 11 - Madep - M3.1

11 - Madep - M3.1 - NEW DEVICES 03
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1991 - EPE-MADEP Joint Sessions > 11 - Madep - M3.1 - NEW DEVICES 03

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   FAILURE MECHANISMS AND NONDESTRUCTIVE TESTING OF POWER BIPOLAR AND MOS GATED TRANSISTORS
By David L. Blackburn [View]
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Abstract: Failure mechanisms and nondestructive testing of power bipolar and MOS gated devices are discussed. Bipolar transistor failures are initiated at relatively low temperatures and these devices can be tested nondestructively. Modern MOS gated device failure is initiated at temperatures far in excess of those normally considered safe and can not be tested nondestructively today. The key to nondestructive testing is the ability to sense the onset of failure and to then remove all power from the transistor before the device temperature rises high enough to cause damage.

   TURN-OFF BEHAVIOR OF STRUCTURED MCT CELLS
By H. Dettmer; H. Lendenmann; J. Bürgler; S. Müller; W. Fichtner [View]
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Abstract: We have investigated the turn-off behavior of MOS-controlled thyristors (MCTs) using multi-dimensional numerical process and device modeling tools. The device structures include single MCT cells as well as multi-cell ensembles. The calculations emulate real-life situations by incorporating external networks (inductors, resistances, diodes, capacitors). The results show both the excellent current handling capabilities of individual cells and the susceptibility of ensembles to current inhomogenities. We find filamentation to be a strong function of the structural optimization of an ensemble. More important, we can show that it can be suppressed by proper cell arrangement. The simulation results have been verified by measurements of MCT's with different cell structures.

   TEMPERATURE VARIATION EFFECTS ON THE SWITCHING CHARACTERISTICS OF MOS-GATE DEVICES
By J.L. Hudgins; S. Menhart; W.M. Portnoy; V.A. Sankaran [View]
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Abstract: The switching performance of power mosfet's, insulated gate bipolar transistors, and mos-controlled thyristors are evaluated and compared with respect to temperature variations from 93 to 468 K. The devices all had a similar forward blocking voltage rating of near 1 kV, and current ratings that were matched as closely as possible. All the devices were operated up to their maximum possible frequency, 2 MHz, 500 kHz, and 200 kHz, for the MOSFETs, IGBT's, and MCT's, respectively.

   HIGH POWER MOS-CONTROLLED-THYRISTOR USING THE PARALLEL CONTACTING TECHNOLOGY FOR DEVICES ON THE SAME WAFER
By C. Ronsisvalle; G. Ferla; P.E. Zani [View]
[Download]

Abstract: It has been realized a very high power MCT device (2kV, 5kA) of 80mm in diameter. In order to produce a such device with an acceptable yield, it is necessary to utilize the "Wafer Repairing Technique", that consist in making on the same wafer or chip an over number of elementary devices in parallel and in checking them individually, eliminating the rejected ones in the contacting phase. A very high voltage edge termination made by 12 decreasing concentration rings, has been associated to this device.

   OPTIMIZATION OF CATHODE STRUCTURES FOR IMPROVED PERFORMANCE OF MOS CONTROLLED THYRISTORS (MCT)
By F. Bauer; H. Haddon; T. Stockmeier; W. Fichtner; R. Vuilleumier; J.-M. Moret [View]
[Download]

Abstract: We have analysed cathode structures for MCT's in an effort to optimize device performance, i.e. maximum current turn-off capability of large area cell arrays. A combination of a p-channel DMOS technology and an adapted thyristor process was used to fabricate arrangements of single cells, cell rows, stripes and various arrays of up to 21'000 cells with forward blocking voltages exceeding 2'000 V. The analysis of cellular type MCTs with cell pitches between 15 μm and 30 μm revealed a cell scaling law for MCT cell arrays: the turn-off capability is inversely proportional to the cell pitch. Using a cellular cathode structure permits a higher turn-off current level as compared to a cathode design composed of continous stripes. The maximum turn-off current density in large MCT arrays is drastically reduced as compared to single cells. Despite this fact, current densities of 70 A/cm2 (Va= 2 kV) can be controlled under snubberless clamped inductive load conditions with MCTs with an actice area of 8.4 mm2.

11 - Madep - M3.1 - NEW DEVICES 03
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1991 - EPE-MADEP Joint Sessions > 11 - Madep - M3.1 - NEW DEVICES 03
	[return to parent folder]

	FAILURE MECHANISMS AND NONDESTRUCTIVE TESTING OF POWER BIPOLAR AND MOS GATED TRANSISTORS By David L. Blackburn	[View] [Download]
Abstract: Failure mechanisms and nondestructive testing of power bipolar and MOS gated devices are discussed. Bipolar transistor failures are initiated at relatively low temperatures and these devices can be tested nondestructively. Modern MOS gated device failure is initiated at temperatures far in excess of those normally considered safe and can not be tested nondestructively today. The key to nondestructive testing is the ability to sense the onset of failure and to then remove all power from the transistor before the device temperature rises high enough to cause damage.

	TURN-OFF BEHAVIOR OF STRUCTURED MCT CELLS By H. Dettmer; H. Lendenmann; J. Bürgler; S. Müller; W. Fichtner	[View] [Download]
Abstract: We have investigated the turn-off behavior of MOS-controlled thyristors (MCTs) using multi-dimensional numerical process and device modeling tools. The device structures include single MCT cells as well as multi-cell ensembles. The calculations emulate real-life situations by incorporating external networks (inductors, resistances, diodes, capacitors). The results show both the excellent current handling capabilities of individual cells and the susceptibility of ensembles to current inhomogenities. We find filamentation to be a strong function of the structural optimization of an ensemble. More important, we can show that it can be suppressed by proper cell arrangement. The simulation results have been verified by measurements of MCT's with different cell structures.

	TEMPERATURE VARIATION EFFECTS ON THE SWITCHING CHARACTERISTICS OF MOS-GATE DEVICES By J.L. Hudgins; S. Menhart; W.M. Portnoy; V.A. Sankaran	[View] [Download]
Abstract: The switching performance of power mosfet's, insulated gate bipolar transistors, and mos-controlled thyristors are evaluated and compared with respect to temperature variations from 93 to 468 K. The devices all had a similar forward blocking voltage rating of near 1 kV, and current ratings that were matched as closely as possible. All the devices were operated up to their maximum possible frequency, 2 MHz, 500 kHz, and 200 kHz, for the MOSFETs, IGBT's, and MCT's, respectively.

	HIGH POWER MOS-CONTROLLED-THYRISTOR USING THE PARALLEL CONTACTING TECHNOLOGY FOR DEVICES ON THE SAME WAFER By C. Ronsisvalle; G. Ferla; P.E. Zani	[View] [Download]
Abstract: It has been realized a very high power MCT device (2kV, 5kA) of 80mm in diameter. In order to produce a such device with an acceptable yield, it is necessary to utilize the "Wafer Repairing Technique", that consist in making on the same wafer or chip an over number of elementary devices in parallel and in checking them individually, eliminating the rejected ones in the contacting phase. A very high voltage edge termination made by 12 decreasing concentration rings, has been associated to this device.

	OPTIMIZATION OF CATHODE STRUCTURES FOR IMPROVED PERFORMANCE OF MOS CONTROLLED THYRISTORS (MCT) By F. Bauer; H. Haddon; T. Stockmeier; W. Fichtner; R. Vuilleumier; J.-M. Moret	[View] [Download]
Abstract: We have analysed cathode structures for MCT's in an effort to optimize device performance, i.e. maximum current turn-off capability of large area cell arrays. A combination of a p-channel DMOS technology and an adapted thyristor process was used to fabricate arrangements of single cells, cell rows, stripes and various arrays of up to 21'000 cells with forward blocking voltages exceeding 2'000 V. The analysis of cellular type MCTs with cell pitches between 15 μm and 30 μm revealed a cell scaling law for MCT cell arrays: the turn-off capability is inversely proportional to the cell pitch. Using a cellular cathode structure permits a higher turn-off current level as compared to a cathode design composed of continous stripes. The maximum turn-off current density in large MCT arrays is drastically reduced as compared to single cells. Despite this fact, current densities of 70 A/cm2 (Va= 2 kV) can be controlled under snubberless clamped inductive load conditions with MCTs with an actice area of 8.4 mm2.