Reverse-Conducting Insulated Gate Bipolar Transistor: A Review of Current Technologies

Abstract

The Reverse Conducting IGBT has several benefits over a separate IGBT and diode solution and has the potential to become the dominant device within many power electronic applications; including, but not limited to, motor control, resonant converters, and switch mode power supplies. However, the device inherently suffers from many undesirable design trade-offs which have prevented its widespread use. One of the most critical issues is the snapback seen in the forward conduction characteristic which can prevent full turn-on of the device and result in the device becoming unsuitable for parallel operation (required in many high voltage modules). This phenomenon can be suppressed but at the expense of the reverse conduction performance. This paper provides an overview of the technical design challenges presented by the RC-IGBT structure and reviews alternative device concepts which have been proposed in literature. Analysis shows that these alternate concepts either present a trade-off in performance characteristics, an inability to be manufactured, or a requirement for a custom gate drive.

Recent advances and trend of HEV/EV‐oriented power semiconductors – an overview

“…Nevertheless, there are still some technical and process issues on the semiconductor aspect. The features and present challenges of the RC-IGBT module from the application perspectives are summarised in Table 5 [60][61][62]. Another trend is the sensor integration on a silicon chip for the condition monitoring [63][64][65][66].…”

Investigation of the Dual Implant Reverse-Conducting SuperJunction Insulated-Gate Bipolar Transistor

“…HE RC-IGBT was first proposed in 1987 with a collector shorted, p-channel IGBT [1] building upon the concept in [2], where to integrate the diode structure within the IGBT n+ regions (anode shorts) are implanted into the p-collector region [3], [4]. It has several advantages: a reduction in the overall silicon area compared to a separate IGBT and diode solution; a reduction in module assembly, wafer processing and testing cost as well as improved reliability offered by a reduction in the number of bond wires; the RC-IGBT is more suitable for high junction temperature operation, and there is the possibility of optimising gate signals to allow better trade-off between the onstate voltage drop and the reverse recovery losses of the diode [5]. Yet despite these benefits, widespread use of the RC-IGBT within high voltage, hard switching applications are limited as the device suffers from an undesirable snapback in the currentvoltage characteristics (MOSFET shorting effect) [5].…”

“…In this alternative SJ device, it was shown that pillar location is independent of the features of the cathode, thus making processing simpler as there is no need for alignment [9]. It also decouples the anode design from the cathode enabling the designer to better control the saturation current and short circuit capability [9], and has the advantage over the AB RC-IGBT that the n/p pillars in the SJ device do not also need to be optimised for breakdown capability [5]. Similar improvements in snapback was reported for this anode SJ implantation, but, as for the cathode-side SJ device, to remove the snapback entirely the SJ implant had to extend through the entire drift region, which cannot be manufactured [9].…”

“…1 is a schematic representation of the dual implant SJ RC-IGBT. It is based upon the standard RC-IGBT structure with anode shorts [5], but the drift region contains two regions of SJ pillars, one from the cathode side and a second from the anode side. The direct wafer bonding technique could be employed to manufacture this device.…”

Snapback‐free reverse conducting IGBT with p‐poly trench‐collectors

“…Introduction: The reverse conducting insulated gate bipolar transistor (RC-IGBT) has an integrated antiparallel free-wheeling diode (FWD) in one chip [1]. Compared to the pair of IGBT and FWD, RC-IGBT has lower cost and less parasitic effects, and it is more attractive in power electronic applications [2]. However, the conventional RC-IGBT is not suitable for parallel operation due to its snapback phenomena at forward on-state [2].…”