Abstract
In this paper, Ge surface passivation by GeO2 grown by N2O plasma oxidation is presented and experimentally demonstrated. Results show that stoichiometrically GeO2 can be achieved by N2O plasma oxidation at 350°C. The transmission electron microscope observation reveals that the GeO2/Ge interface is automatically smooth and the thickness of GeO2 is ∼0.9 nm with 120 s N2O plasma oxidation. The interface state density of Ge surface after N2O plasma passivation is about ∼ 3×1011 cm−2eV−1. WithGeO2 passivation, the hysteresis of MOS capacitor with Al2O3 as gate dielectric is reduced to ∼55 mV, compared to 130 mV of the untreated one. The Fermi-level at GeO2/Ge interface is unpinned, and the surface potential is effectively modulated by the gate voltage, which is promising for high performance NMOSFETs fabrication.
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Lin, M., An, X., Li, M. et al. Ge surface passivation by GeO2 fabricated by N2O plasma oxidation. Sci. China Inf. Sci. 58, 1–5 (2015). https://doi.org/10.1007/s11432-014-5180-y
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DOI: https://doi.org/10.1007/s11432-014-5180-y