HfO2-based Metal-Oxide-Semiconductor Capacitors on n-InGaAs Substrate with a Thin Germanium Passivation Layer

Hyoung-Sub Kima), I. Ok, M. Zhang, F. Zhu, S. Park, J. Yum, S. Koveshnikov*, W. Tsai*, V. Tokranov**,

M. Yakimov**, S. Oktyabrsky**, and Jack C. Lee

*Intel Corporation, Hillsboro, Oregon 97124, **The University at Albany-SUNY, New York 12203, Dept. of Electrical Engineering, The University of Texas at Austin, Austin, Texas 78758a)
email:
hskim1997@mail.utexas.edu, phone: 512-471-1627

Keywords: InGaAs, GaAs, MOSCAP, HfO2, Passivation, Capacitance, Ge

Abstract

The effect of a germanium (Ge) interfacial passivation layer (IPL) on the capacitance-voltage (C-V) and current density-voltage (J-V) characteristics of TaN/HfO2/Ge/n-InGaAs metal-oxide-semiconductor capacitors (MOSCAPs) were studied. In comparison to MOSCAPs on GaAs, the results from the accumulation region were quite similar, while the C-V curves in the inversion region were substantially different owing to the different energy bandgap. By using 8 ~ 10 Å Ge IPL and 60~70 Å HfO2, MOSCAPs on InGaAs exhibited an equivalent oxide thickness (EOT) of ~ 11 Å and gate dielectric leakage current density (Jg) of ~ 10-5 A/cm2 at Vg-VFB =1 V with good C-V frequency dispersion, whereas poor electrical characteristics were obtained from the devices without a thin Ge IPL. These results show that a thin Ge IPL in optimal conditions passivates InGaAs surface effectively and provides a high quality interface.

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