engleski

Measurement of charge collection profiles in irradiated silicon diodes by lateral IBIC technique

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 × 1012 ions/cm2. 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.

semiconductors electronic properties; ion beam induced charge collection; radiation damage

Rad je prezentiran na skupi 10th International Conference on Nuclear Microprobe Technology and Applications and 2nd International Workshop on Proton Beam Writing : Nuclear Microprobe Technology and Applications (ICNMTA2006) and Proton Beam Writing (PBW II), održanom u Shangri La Rasa Resort, Singapore.