High-Voltage Emitter Short Diode (ESD)

We report the effects of emitter short structures, ESD(a) and ESD(b), as well as the effect of a very shallow emitter, on the reverse recovery characteristics for 4 kV high-voltage diodes. It was found that a diode with a shallow p-emitter and emitter short structures attains half the reverse recovery current I rr, compared to conventional punch-through p-i-n diodes. ESD has a further advantage in that the leakage current is as low as that of conventional p-n junction diodes, even at 125° C. ESD structures with a fine n+ and p+ short structure attain no parasitic effect, even at a current density of 100 A/cm2 and di/ dt of -1000 A/µs.