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We have fabricated high voltage ( 3.5 kV ) MCT and IGBT devices simultaneously on the same silicon wafer to compare their static and dynamic characteristics. A DMOS technology was adapted to allow for the realization of n-channel ( IGBT ) and p-channel ( MCT ) device structures in the same complimentary DMOS ( CDMOS ) process. The high voltage blocking capability was achieved using the same planar junction termination structure for both types of devices. MOS controlled thyristors offer destinctly lower on-state losses as IGBTs, although low on-state voltages in the range of 2 to 4 V were measured for the IGBT devices with 3.5 kV blocking capability. The maximum turn-off capability was found to be determined by the Si material parameters and is therefore identical for both devices.

Measured and simulated turn-off curves of high-voltage MCTs (MOS-controlled thyristors) and IGBTs (insulated-gate bipolar transistors) are presented. Device simulation results show that the inherently faster-switching IGBT is much more affected by dynamic avalanche phenomena than the MCT. It is also shown that the avalanche-injected carriers can be removed by shorting the anode layer, resulting in a much higher turn-off performance for both devices. Because of the lower charge and therefore the higher dV/dt, the ionization rate is higher in the IGBT than in the MCT. >

After a short comparison of the basic characteristics of 20 A, 2 kV MOS controlled thyristors (MCT) and insulated gate bipolar transistors (IGBT), both device concepts are analysed in the same hard switching circuit environment using mixed mode 2D device and circuit simulation tools. The focus of this comparative study is put on the controllability of current and voltage transients mandatory for device protection in unsnubbered circuits. This goal is easily met with the IGBT coupling feedback into the gate; MCTs enter oscillatory modes under such conditions and may eventually be destroyed.

The dynamic characteristics of large MCT (MOS controlled thyristor) ensembles have been improved by integrating IGBT (insulated-gated bipolar transistor) cells for turn-on and different schemes of cathode and anode shorting for turn-off. Such MCT-IGBT ensembles with integrated shorts are able to turn off 4 A (240 A-cm/sup -2/) at 1000 V in typically 1.5 mu s in the inductive clamped mode. The authors report on the effectiveness of these different approaches and their parasitic influence on the turn-on characteristic and the maximum turn-off current capability. The implementation of permanent cathode shorts has lead to an increase of the maximum turn-off current of large MCT ensembles, whereas anode shorting leads to faster turn-off and lower tail currents. A careful design of the IGBT turn-on cell and placement is required for proper MOS turn-on even at low anode voltages. >

Power integrated circuits and devices are at the heart of many system applications ranging from more or less conventional analog circuits operated at non-standard voltage levels to complex systems composed of parallel arrangements of multi-layer devices such as MOSFETs, bipolar transistors and thyristor devices. Driven by the rapid advances in device technology and the demands for new, more efficient electronic systems, new generations of MOS controlled power devices are entering the market place. This is true even for very high voltage applications, where the once secure position of the Gate-Turn-Off Thyristor (GTO) is being challenged today by new MOS-controlled switch elements such as the Insulated Gate Bipolar Transistor (IGBT).

The impact of the injection efficiency of unshorted anode p/sup +/emitters on the static and dynamic electrical characteristics of high voltage non-punchthrough IGBTs is analysed using mixed mode two-dimensional device and circuit simulation tools. The results are compared to IGBT device structures with shorted anodes. IGBTs with high and low efficiency anode emitters can be designed to have the same conduction losses despite major differences in the p/sup +/emitter doping profiles and the carrier lifetime. Turn-off losses are in general higher for IGBTs with homogeneous low efficiency emitters. Pushing the trade-off between conduction and turn-off losses to the level set by anode shorted IGBTs is also feasible for homogeneous, low efficiency p/sup +/emitter devices, though it requires approaching the technological limits of injection efficiency and carrier lifetime.