Current mechanisms in silicon PIN structures processed with various technologies

This study presents a comparison of dark characteristics of PIN (p⁺-semi-intrinsic-n⁺) structures fabricated with several technologies on high-resistivity silicon wafers. The study considers the temperature dependence of the various current mechanisms. Significant and consistent differences were observed in the reverse current-voltage characteristics of the various samples, while capacitance-voltage profiles remain similar, indicating no process related variations in the effective space charge distribution. The results show that the activation energy of the reverse current in samples processed by various technologies differs, which may indicate that the Shockley Read Hall generation occurs through centers at different energies. Specifically, in some samples the reverse currents are dominated by generation-recombination centers located ∼0.2 eV from the mid-gap, while in other samples the currents are dominated by the 'standard' mid-gap generation-recombination centers. The difference is shown to be mostly technology related with little dependence on the starting material. To emphasize the comparative nature of this study, similar wafers and masks were used in all the reported technologies.