A new IGBT structure with a wider safe operating area (SOA)

A new IGBT structure incorporating a shallow diverter between adjacent cells is proposed in this paper with the aim of widening the Forward Bias Safe Operating Area (FBSOA) of the IGBT. The latchup limit of the IGBT increased from 700 A/cm² to 1100 A/cm² in case of the n-channel IGBT and from 1200 A/cm² to 2100 A/cm² for the p-channel IGBT. Although there was a no improvement in the dynamic avalanche limit in the case of the p-channel IGBT, it improved significantly for the n-channel IGBT making its FBSOA much wider than that of the conventional IGBT. The incorporation of the diverter was found to result in an increase in the forward voltage drop (at a current density of 200 A/cm²) from 1.7 V to 2.3 V and -2.3 V to -3.9 V for the n- and the p-channel IGBT, respectively