In this thesis, an
interface passivation by a lattice matched atomic layer deposition (ALD)
epitaxial magnesium calcium oxide (MgCaO) on wide-bandgap gallium nitride (GaN)
has been applied for the first time and expensively studied via various
characterization methods (including AC conductance methods, pulsed
current-voltage, and single pulse charge pumping). Also, beta-Ga2O3 with a monoclinic crystal
structure that offers several surface oriented channels has been demonstrated
as potential beta-Ga2O3 FET. On the other hand,
low frequency noise studies in 2-D MoS2 NC-FETs was reported for the first
time. Low frequency noise of the devices is systematically studied depending on
various interfacial oxides, different thicknesses of interfacial oxide, and ferroelectric
hafnium zirconium oxide. Interestingly enough,
the low frequency noise is found to decrease with thicker ferroelectric HZO in
the subthreshold regime of the MoS2 NC-FETs, in stark contrast to the
conventional high-k transistors. Also, the
ferroelectric switching speed is found to be related with the maximum electric
field applied during the fast gate voltage sweep, suggesting the internal
ferroelectric switching speed can be even faster depending on the device’s
electrical bias conditions and promises a high speed performance in our
ferroelectric HZO