The control of the carrier lifetime proﬁle in semiconductor power devices is of fundamental importance to optimize device parameters. With respect to traditional technologies such as diﬀusion of metallic impurities, light ion irradiation at low doses provides precise spatial localization of defects acting as carrier traps and recombination centres. Hence, the generation of suitable lifetime proﬁles obtained by controlling ion ﬂuence and energy allows the reduction of turn-oﬀ times and switching losses in power electronic devices. In order to characterise the eﬀects of ion irradiation on carrier lifetime proﬁles, we have used the ion beam induced charge collection (IBIC) technique in lateral geometry to measure charge collection eﬃciency (CCE) proﬁles in silicon p+/n/n+ diodes under diﬀerent applied bias conditions before and after a frontal 6.5 MeV He++ ion implantation at a total ﬂuence of 2 · 10^12 ions/cm^2. After the irradiation, the proﬁle shows a clear drop of charge collection eﬃciency which occurs at the end of the ion range. The formalism based on Shockley–Ramo–Gunn’s theorem was applied to interpret the CCE proﬁles in both virgin and irradiated samples and to assess the free carrier lifetime proﬁle modiﬁcation following the radiation damage.
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