The $\hbox{nn}^{+}$-Junction as the Key to Improved Ruggedness and Soft Recovery of Power Diodes

Comparison of critical current filaments in IGBT short circuit and during diode turn-off

“…1 (top)). The electric-field gradient in this cathode-side SCR has the opposite sign compared to the gradient in the anode-side SCR, because of n > N D + p in the cathode-side SCR, with n (p) denoting the electron (hole) density and N D the bulk doping [2]. If the width of the SCR gets wide enough and the reverse current is high enough, the lateral distribution of the current density becomes inhomogeneous.…”

Influence of carrier lifetime distribution on the current filament in high voltage diode

“…N eff = N D + p, leads to the increase of electric field strength. Therefore, the dynamic avalanche will occur, even the voltage is much lower than the static breakdown voltage [15,16]. In [4], the differences between the formation reasons and the variation behaviors of cathode side and anode side filaments were explained by analyzing the plasma front velocities during reverse recovery, and the results have shown that the filaments at the anode and cathode sides are both relevant to the negative differential resistance (NDR) in the I-V characteristic.…”

3D electro-thermal simulations of wide area power devices operating in avalanche condition

“…With this value of current in fact, device operates in negative differential resistance region and correct behavior of the implemented simulator can be evaluated in this condition. As effect of negative resistance, current distribution becomes non uniform during the time [10][11][12]. Initially device starts with uniform temperature and a current which is slightly non uniform due to differences in the layout and to parasitic elements.…”