On the Investigation of the “Anode Side” SuperJunction IGBT Design Concept

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

“…For both devices, breakdown occurs at the n+ injector layer at the cathode, but the presence of the SJ pillars alters the electric field distribution such that a larger voltage can be supported for a given device thickness. As a result, a SJ device can be made thinner for the same breakdown voltage to improve on-state performance, in line with previous studies [7], [9], [18]. Fig.…”

“…This study proposes applying two SJ implants, one from the cathode side and a second one from the anode side, and investigates the requirement for alignment of these pillars. This work builds upon the concepts and results as given in [7], [9], specifically for an RC-IGBT structure. Fig.…”

“…More recent studies have focussed on the possibility of applying the SJ to the anode side [9], similar to the Alternating Buffer Reverse Conducting IGBT (AB RC-IGBT) concept [10]. 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].…”

“…More recent studies have focussed on the possibility of applying the SJ to the anode side [9], similar to the Alternating Buffer Reverse Conducting IGBT (AB RC-IGBT) concept [10]. 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].…”

“…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].…”