Tailoring of the switching time of p-n junction diodes by inducing defects in the p-region with swift heavy ions

Silicon diodes (p⁺n) of turn-off time, t_π~1000 ns, were irradiated with 65 MeV oxygen ions to induce defects only in the p-region. The turn-off time, t_π of the diodes decreased from its value of 1000 ns to 500 ns at a fluence of 10¹⁰ ions/cm² and to 250 ns at a fluence of 5×10¹² ions/cm². The decrease in the turn-off time is attributed to the reduction in the hole-stored -charge in the n-region and also due to the increase in the reverse current, as a consequence of the defects induced in the p-region. A plot of the turn-off time, t_π vs In(1+I_F/l_R) revealed that the life-time of holes, ρ_p in the n-region remained unaffected after a fluence 10¹⁰ ions/cm². These results indicate that by inducing defects near the junction in the p-region, the turn-off time, t_π of silicon diodes can be reduced without killing the life-time of the holes, τ_p in the n-region