D.R. Muss

Bio: D.R. Muss is an academic researcher from Westinghouse Electric. The author has contributed to research in topics: Carrier lifetime. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.

Switching mechanism in the n-p-n-p silicon controlled rectifier

Abstract: The OFF state current-voltage characteristics of a two-terminal n-p-n-p silicon controlled rectifier are predicted by considering one-dimensional diffusion of minority carriers in the bulk regions and recombination and generation of carriers in the junction space-charge regions. It is concluded that the temperature dependence of the breakover voltage is strongly dependent on the lifetimes in the space-charge regions of the junctions. Evidence is shown that the carrier lifetime in the space-charge region of an alloyed junction may be less than 10-9seconds even though the lifetime in the bulk is of the order of 10-6seconds. The effect of gate current on the device characteristic and gated turn-off are treated in a very approximate manner.

Gate turn-off in p-n-p-n devices

Abstract: A simple two-dimensional model for gated turn-off of a p-n-p-n device is used to derive an expression relating the storage time and the turn-off gain. The observed dependence of storage time on turn-off gain fits the derived expression well for devices specially fabricated consistant with the assumptions of the model. The fall time is discussed qualitatively.

On the variation of small-signal alphas of a p-n-p-n device with current

Abstract: The physical mechanisms that govern the variation of alphas of a silicon p - n - p - n device with current are investigated and an analytical expression for the small-signal alphas is derived. It is shown that both diffusion and electric field contribute to the transport of carriers and, therefore, affect the device transport factors and injection efficiencies. The value of alpha can be tailored to the desired range by choosing properly the base width, the diffusion length and the doping levels. A numerical example is worked out and the small-signal alpha, the d.c. alpha, the transport factor and the injection efficiency are plotted as functions of current for several values of base width of the p - n - p section of a p - n - p - n device. It is seen that the small-signal alpha is always greater than the d.c. alpha in the current range investigated.

A high-voltage, high-temperature reverse conducting thyristor

Abstract: This paper describes the structure and electrical characteristics of a silicon p-n-p-n inverter switch which has been fabricated to demonstrate the feasibility of obtaining both high-voltage and high-temperature capability in the same device while still maintaining reasonable dynamic properties. It was realized that in most inverter systems, feedback rectifiers are required, and thus the reverse blocking capability of a thyristor is not utilized. This was used to advantage in the design of a thyristor by integrating an anti-parallel rectifier into a conventional thyristor structure. Although this approach results in a thyristor having a negligible reverse blocking capability in comparison to commercially available power thyrisitors, the potential advantages of lower conduction losses, high maximum junction temperatures, and integrated antiparallel rectifier may be attractive for use in inverters. Reverse conducting thyristors designed in this fashion have been operated with reasonable turnoff times at a forward blocking voltage of 1000 volts while at case temperatures of up to 230°C.

Characteristics of a high-current, high-voltage Shockley diode

Abstract: This paper describes design, development, characterization, and operation of a two-terminal, high-current, high-voltage silicon four-layer diode. The main feature of this new four-layer diode is a voltage-current characteristic which is, prior to switching, similar to that of an avalanche diode. This property is achieved by short-circuiting one emitter-base junction, resulting in a grid-type emitter geometry. The short-circuiting takes place over the entire device area in order to maintain uniform turn-on and uniform current conduction. Devices switching at 1000 volts or higher, with peak pulse current capability of 1000 amperes or more, are described. To achieve very high switching voltages, the stacking of two or three silicon chips was found to be useful. Extended tests Were performed at various combinations of pulsewidths (0.5 to 12 µs), repetition rates (0.2 to 2000 pulses per second), and operating times (0.1 to 2500 hours). The test circuits and the resulting turn-on and recovery times are summarized, Failure analysis establishes hot spot development or thermal fatigue as possible failure mechanisms. Since series operation of many devices is possible without complicated dividing networks, the complexity of pulse modulator circuitry is reduced, and resonantly charged circuits can exhibit a high degree of operation reliability and temperature insensitivity.

Current state-of-the-art and future prospects for power semiconductor devices in power transmission and distribution applications

Abstract: Since the first commercially viable thyristors appeared in the early 1960s, there has been a dramatic increase in the switched power ratings and versatility of high-voltage power semiconductor devices. By the mid 1970s, thyristors with switched power ratings of several MVA were being applied in high voltage dc transmission systems and static VAr compensators. The introduction, in the 1980s, of controlled turn-off devices, such as the gate turn-off thyristor (GTO) and insulated gate bipolar transistor (IGBT), broadened the application of high-voltage power devices to hard-switched converters and, by the start of the 21st century, controllable silicon power devices were available with voltage ratings of 12 kV and switched power capabilities of up to 40 MVA. A review of the current state-of-the-art in silicon high-voltage power semiconductor technology covers gate-commutated thyristors (GCT, IGCT) and IGBT devices, including the injection-enhanced IGBT or IEGT. Despite these considerable achievements, there ...