A High Bidirectional Blocking Capability Insulated-Gate Bipolar Transistor With Ultralow Loss

Abstract

A novel high bidirectional blocking capability and ultralow loss insulated-gate bipolar transistor with a shorted collector field plate (SCFP) and field stop (FS) layers [SCFP FS reverse blocking (RB)-IGBT] is proposed and its mechanism is investigated by simulations. The device features an SCFP coupled with discontinued N2 layers and an N1 layer as FS layers. First, in the RB process, the SCFP assists in depleting the N2 layers and mergers the depletion boundary, thus, the depletion boundary could easily expand in the lightly doping n-drift region and is stopped by the N1 layer together with trenches, ensuring a high reverse breakdown voltage (BV $_{R}$ ). Second, the trenches are beneficial to shield the high electric field around the P-body/N1 junction (J1) even in condition of a high doping N1, without penalty in forward breakdown voltage (BV $_{F}$ ). Note that a high doping N1 is constructive to obtain a high BV $_{R}$ and low ON-state voltage drop ( ${V}_{ \mathrm{\scriptscriptstyle ON}}$ ) owing to the enhanced carrier stored effect. Third, the device exhibits a low turn-OFF loss ( ${E}_{ \mathrm{\scriptscriptstyle OFF}}$ ) since an electron accumulation layer is formed along the SCFP to extract electrons rapidly. The SCFP FS RB-IGBT realizes bidirectional blocking capability ≥800 V and ${E}_{ \mathrm{\scriptscriptstyle OFF}}~49$ % and 67.2% lower than those of bidirectional electric field enhanced FS RB-IGBT and non-punch-through RB-IGBT, respectively.