%0 Electronic Article %A Renz, A. B. and Shah, V. A. and Vavasour, O. J. and Bonyadi, Y. and Li, F. and Dai, T. and Baker, G. W. C. and Hindmarsh, S. and Han, Y. and Walker, M. and Sharma, Y. and Liu, Y. and Raghothamachar, B. and Dudley, M. and Mawby, P. A. and Gammon, P. M. %I AIP Publishing %D 2020 %D 2020 %G English %@ 0021-8979 %@ 1089-7550 %~ Katalog UB TU-Chemnitz %T The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment %V 127 %J Journal of Applied Physics %V 127 %N 2 %U http://dx.doi.org/10.1063/1.5133739 %X Molybdenum (Mo)/4H-silicon carbide (SiC) Schottky barrier diodes have been fabricated with a phosphorus pentoxide (P2O5) surface passivation treatment performed on the SiC surface prior to metallization. Compared to the untreated diodes, the P2O5-treated diodes were found to have a lower Schottky barrier height by 0.11 eV and a lower leakage current by two to three orders of magnitude. Physical characterization of the P2O5-treated Mo/SiC interfaces revealed that there are two primary causes for the improvement in electrical performance. First, transmission electron microscopy imaging showed that nanopits filled with silicon dioxide had formed at the surface after the P2O5 treatment that terminates potential leakage paths. Second, secondary ion mass spectroscopy revealed a high concentration of phosphorus atoms near the interface. While only a fraction of these are active, a small increase in doping at the interface is responsible for the reduction in barrier height. Comparisons were made between the P2O5 pretreatment and oxygen (O2) and nitrous oxide (N2O) pretreatments that do not form the same nanopits and do not reduce leakage current. X-ray photoelectron spectroscopy shows that SiC beneath the deposited P2O5 oxide retains a Si-rich interface unlike the N2O and O2 treatments that consume SiC and trap carbon at the interface. Finally, after annealing, the Mo/SiC interface forms almost no silicide, leaving the enhancement to the subsurface in place, explaining why the P2O5 treatment has had no effect on nickel- or titanium-SiC contacts. %Z https://katalog.bibliothek.tu-chemnitz.de/Record/ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuMTA2My8xLjUxMzM3Mzk %U https://katalog.bibliothek.tu-chemnitz.de/Record/ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuMTA2My8xLjUxMzM3Mzk