Enhanced Interface Characteristics o PA-ALD HfOxNy/InGaAs MOSCAPs Using IPA Oxygen Reactantand Cyclic N-2 Plasma

초록

This letter reports high-quality plasmaassisted atomic-layer-deposited HfOxNy by using isopropyl alcohol (IPA) oxidant and cyclic N-2 plasma treatment demonstrated on n-type In0.53Ga0.47As. Improved interface characteristics, with suppressed frequency dispersion and surface oxidation, were demonstrated and resulted in significantly decreased interface trap density (D-it) of 4.5 x 10(11) eV(-1) cm(-2) at the mid-gap level with outstanding inversion behaviors. In addition, to verify true inversion, transition frequency (omega(m)) of 4 kHz was extracted. The improvement mechanism of the proposed technology is assumed to be that nitrogen plasma reduces oxygen vacancies that act as oxygen diffusion paths and with the use of IPA oxidant the interface would be strongly protected during pre- and post-dielectric deposition.

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