I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. Abstract This thesis presents a study of the bias-induced threshold voltage metastability phenomenon of the hydrogenated amorphous silicon (a-Si:H) thin f...

Lee, Yi-Mu. Breakdown and reliability of CMOS devices with stacked oxide/nitride and oxynitride gate dielectrics prepared by RPECVD. (Under the direction of Professor Gerald Lucovsky) Remote-plasma-enhanced CVD (RPECVD) silicon nitride and silicon oxynitride alloys have been proposed to be the attractive alternatives to replace conventional oxides as the CMOS logic and memory technology node is...

The potential performance of implant free heterostructure In0 3Ga0 7As channel MOSFETs with gate lengths of 30, 20, and 15 nm is investigated using state-of-the-art Monte Carlo (MC) device simulations. The simulations are carefully calibrated against the electron mobility and sheet density measured on fabricated III-V MOSFET structures with a highdielectric. The MC simulations show that the 30 ...

Design of a 3.3V comaptible 2.5V TTL-toCMOS bidirectional I/O buffer is proposed. Gate oxide protectiom was implemented without active voltage degradation, which reduces static and dynamic current levels and improves noise immunity for the low voltage circuit of this kind. Fast removal of stored charge further improve gate oxide protection and circuit recovery from overvoltage condition. Circui...

A novel method for the reduction of subthreshold slope below the room-temperature Boltzmann limit of 60 mV/dec for a field-effect transistor based on negative differential capacitance is proposed. This effect uses electric field induced electrostriction of a piezoelectric gate barrier of the transistor. The mechanism amplifies the internal surface potential over the applied gate voltage. This i...

Four-probe resistance vs temperature and gate voltage are reported for an individual single-wall carbon nanotube rope before and after doping in situ with potassium. All the features in R(T) from unoriented bulk material, before and after doping, are qualitatively reproduced by the rope data. The 5.3 K conductance of the pristine rope decreases with positive gate voltage, while G vs Vg becomes ...

We have demonstrated that photo-thin film transistors (photo-TFTs) fabricated via a simple defect-generating process could achieve fast recovery, a high signal to noise (S/N) ratio, and high sensitivity. The photo-TFTs are inverted-staggered bottom-gate type indium-gallium-zinc-oxide (IGZO) TFTs fabricated using atomic layer deposition (ALD)-derived Al2O3 gate insulators. The surfaces of the Al...

The optical transparency and high electron mobility of graphene make it an attractive material for photovoltaics. We present a field-effect solar cell using graphene to form a tunable junction barrier with an Earth-abundant and low cost zinc phosphide (Zn3P2) thin-film light absorber. Adding a semitransparent top electrostatic gate allows for tuning of the graphene Fermi level and hence the ene...

We present detailed measurements of the discrete electron-tunneling level spectrum within nanometer-scale cobalt particles as a function of magnetic field and gate voltage, in this way probing individual quantum many-body eigenstates inside ferromagnetic samples. Variations among the observed levels indicate that different quantum states within one particle are subject to different magnetic ani...

A floating gate charge-sharing circuit that can be electrically programmed for precise positive and negative voltage changes, and can be implemented in a standard CMOS VLSI process is presented. With the advantage of its longterm charge-retention, the floating gate charge-sharing circuit is suitable for providing a compact, non-volatile and high-precision analog trimming method to trim the offs...