Engineering of threshold voltages in molecular beam epitaxy-grown Al2O3∕Ga2O3(Gd2O3)∕In0.2Ga0.8As

Y. D. Wu, T. D. Lin, T. H. Chiang, Y. C. Chang, H. C. Chiu, Y. J. Lee, M. Hong, Chao‐An Lin, J. Kwo

Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics Materials Processing Measurement and Phenomena · 2010 · 12 citations · 19 references

Concepts

Abstract

The metal-oxide-semiconductor (MOS) capacitors of Al2O3∕Ga2O3(Gd2O3) on n- and p-type In0.2Ga0.8As with different metal gates exhibited excellent capacitance-voltage (C-V) characteristics and remarkable thermodynamic stability after rapid thermal annealing up to 850°C. The flat-band voltage (Vfb), flat-band voltage shift (ΔVfb), threshold voltage (Vth), and frequency dispersion of the MOS capacitors with different metal gates were extracted from the C-V curves. The Vth values of Al2O3∕Ga2O3(Gd2O3)∕p-In0.2Ga0.8As were calculated to be about 0.04V (Al gate) and 1.15V (Ni gate) and those of Al2O3∕Ga2O3(Gd2O3)∕n-In0.2Ga0.8As −1.94V (Al gate) and −0.88V (Ni gate). The correlation between flat-band voltage and different metal gates indicates unpinned Fermi levels at the metal/dielectric interfaces.

References

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