O. Spulber

MOS control device concepts for AC-AC matrix converter applications: the HCD concept for high-efficiency anode-gated devices

Reverse blocking MOS controlled devices will enable high efficiency ac-ac matrix converter systems to replace dc-linked type circuits. The trend in bidirectional switches is to replace the combination of a unidirectional blocking device and a diode with a monolithic reverse blocking device only. The diode on-state loss is eliminated, part count is reduced, and the system is less bulky. This paper discusses the various reverse blocking concepts suitable for MOS controlled devices for high voltage matrix converter applications. They include the junction isolation, the trench isolation, and the anode-gated (AG) concepts. AG is the only concept not technologically limited beyond 1200 V. However, increasing drift region thickness with voltage rating necessitates innovations to achieve fast switching and low losses without compromising V/sub ce(sat)/. Herein we propose the high channel density concept to further improve the efficiency of AG devices. Simulation results indicate the concept drastically reduces turnoff losses and improve switching speed.

A novel gate geometry for the IGBT: the trench planar insulated gate bipolar transistor (TPIGBT)

This letter demonstrates a simple way to improve the performance of a planar, fine lithography insulated gate bipolar transistor (IGBT), by incorporating a trench gate between the cathode cells. The results of this new trench-planar IGBT (TPIGBT) clearly demonstrate a significant reduction in the voltage drop without degrading the breakdown voltage. The switching analysis indicates that the TPIGBT represents a good trade-off between planar and trench structures. By separating the trench gate requirements away from the cathode cells, the technology development cycle and costs can be reduced. Furthermore, the reduced cell-width and the shallow trench presents TPIGBT as a cost-effective structure for high-voltage applications.

Progress in MOS-controlled bipolar devices and edge termination technologies

An overview of the recent developments in high-voltage power semiconductor MOS-controlled bipolar devices is presented. The Insulated Gate Bipolar Transistor (IGBT) technology is explored from its initial stage up to the latest state-of-the-art developments, in terms of cathode engineering, drift design and anode engineering to highlight the different approaches used for optimisation and the achieved trade-offs. Further, several MOS-gated thyristors, which are aimed to replace the IGBT, are analysed. Moreover, the present paper reviews the various approaches in the fabrication of edge termination used in power device MOS-controlled bipolar devices.

1.7kV NPT V-groove clustered IGBT: fabrication and experimental demonstration

Novel 1.7kV NPT V-groove Trench CIGBT structures have been fabricated using an inexpensive wet etch technology for the trench gates. This approach can significantly reduce the costs inherent in the case of a conventional RIE. Experimental results show current saturation and short-circuit capability. Moreover, the V-groove CIGBT can be switched off without any additional circuit.

Analytic Large-Signal Modeling of Silicon RF Power MOSFETs

This paper provides novel analytic expressions and methodology for predicting the large-signal gain of RF power MOSFETs. The expressions are derived from a model that includes input and output matching impedances, source inductance, and gate resistance. Using the load line concept superimposed on a nonlinear current generator, this paper demonstrates reasonably accurate predictions of gain and gain compression point

Anode-gated MOS controlled thyristor with ultra-fast switching capability

Two-dimensional numerical simulations are used to investigate the effect of increasing the anode MOS channels on the turn-off loss and switching speed. Two devices of 1700V rating have been compared herein under identical conditions: the anode-gated thyristor, the anode-gated clustered IGBT (AG-CIGBT) and anode-gated IGBT (AG-IGBT). The anode MOS channels only conduct during the turn-off phase and drain out excess drift region charge. It is shown that as the number of anode MOS channels is increased turn-off loss is significantly reduced without compromising the low on-state voltage of the AG-CIGBT. The reduction in turn-off loss is more than 62% compared to a conventional structure. His demonstrates that anode-gated thyristor structures can simultaneously provide low n-state voltage, low turn-off loss and fast switching. The results are extremely significant because no bipolar device concept has been reported to achieve all three properties simultaneously.

A novel 'cool' insulated base transistor

A novel, planar, Cool Insulated Base Transistor (IBT) is presented. This is the first MOS-controlled bipolar semiconductor device, which incorporates the super junction concept. The Cool IBT has a current amplification of (/spl beta/+1)* the Cool MOSFET current, where /spl beta/ is the gain of the inherent NPN transistor. Unlike the IGBT, cathode cells of the IBT and MOSFET can be easily paralleled on the same chip. Thus, the device can be turned on at a drain voltage of 0 V, while retaining the low on-resistance of the Cool IBT.

The investigation into the recent mergers and acquisitions in power semiconductor industry

There has been a remarkable increase in mergers and acquisitions in many industries worldwide. In 1999-2002 there were at least 20 spin-offs, acquisitions, or mergers specifically relating to the power semiconductor industry. This paper investigates whether mergers and acquisitions are still the best strategy for power semiconductor companies to gain market presence.

Monolithic integration of low voltage devices in 3 kV planar MOS controlled power devices

Abstract The aim of this paper is to demonstrate, for the first time, the viability of the monolithic integration of low voltage components, such as n and p channel MOSFETs, onto a planar vertical MOS controlled power device. This approach paves the way for realising a monolithic intelligent power chip with enhanced performance and reliability with respect to on-chip temperature, over-current and over-voltage protection circuitry. The detailed simulation results indicate no parasitic effects, both on the low voltage and power devices.

Influence of the N+ floating emitter on the on-state characteristics of the Trench EST

In this paper, the influence of the N+ floating emitter dimensions and doping on the on-state voltage drop and forward-biased safe operating area of the Trench EST are analysed in detail. The influence of the N+ floating emitter doping is demonstrated for the first time. Moreover, we propose to reduce the doping of this region in order to increase the FBSOA of the Trench EST.