We demonstrate InGaAs multigate MOSFETs, so-called FinFETs. The lateral nanowires constituting the channel in these devices have been formed using selective area regrowth, where the surfaces of the nanowires are crystallographic planes. L g = 32 nm devices exhibit peak transconductance of 1.8 mS/μm at V ds = 0.5 V. We also report on RF characterization of these devices. A small-signal hybrid-π model is developed, which includes both the effect of impact ionization and border traps and shows good fit to measurement data. Simultaneously extracted f t and f max are 280 and 312 GHz, respectively, which are the highest reported values of any III-V multiple-gate MOSFET.

An important source of degradation in thin dielectric material layers is the generation and migration of oxygen vacancies. We investigated the formation of Frenkel pairs (FPs) in HfO 2 as the first structural step for the creation of new defects as well as the migration of preexisting and newly built oxygen vacancies by nudged elastic band (NEB) calculations and stress induced leakage current (SILC) experiments. The analysis indicates, that for neutral systems no stable intimate FPs are built, whereas for the charge states q ¼ AE 2 FPs are formed at threefold and at fourfold coordinated oxygen lattice sites. Their generation and annihilation rate are in equilibrium according to the Boltzmann statistics. Distant FPs (stable defects) are unlikely to build due to high formation energies and therefore cannot be accounted for the measured gate leakage current increase of nMOSFETs under constant voltage stress. The negatively charged oxygen vacancies were found to be very immobile in contrast to positively charged V 0 's with a low migration barrier that coincides well with the experimentally obtained activation energy. We show that rather the activation of preexisting defects and migration towards the interface than the defect generation are the cause for the gate oxide degradation.

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