Advances in microelectronics and nanotechnology have generated tremendous interest in the non-Fourier regimes of heat conduction, where the conventional theories based on local equilibrium no longer apply. The non-Fourier regimes include small length scales, where the medium can no longer be treated using bulk properties due to ballistic transport, and short time scales, on the order of the relaxation time of heat carriers, such as in short pulse laser heating. One of the objectives of this thesis is to clarify some misunderstandings in hyperbolic heat equation (HHE), commonly thought as a remedy of Fourier's law at small time scales. The HHE is analyzed from the stand point of statistical mechanics with an emphasis on the consequences of assumptions applied to the Boltzmann transport equation (BTE) when deriving the HHE. In addition, some misperceptions of the HHE, caused by a few experiments and confusion with other physical phenomena, are clarified. It is concluded that HHE should not be interpreted as a more general equation governing heat transport because of several fundamental limitations. The other objective of this thesis is to introduce radiation entropy to the equation of phonon radiative transport (EPRT) for understanding the heat transfer mechanism on a fundamental level which can be applied to both diffusion and ballistic heat conduction in dielectric solids. The entropy generation due to phonon transport is examined along with the definition of a phonon brightness temperature, which is direction and frequency dependent. A better understanding of non-Fourier heat conduction will help researchers and engineers to choose appropriate theories or models in analyzing thermal transport in nanodevices.

An experimental and theoretical approach is taken to determine the effect of a heterojunction on the effective work function in a metal/high-? gate stack, the characteristics of aqueous hydrochloric acid cleaned (aq-HCl) GaN surface and the interface between GaN and Al2O3, HfO2 and GaON. The investigation of the effect of a heterojunction on the effective work function in a metal/high-? gate stack found that when a Ge/Si heterostructure on silicon is lightly doped and sufficiently thin, the work function can be extracted in a manner similar to that for a simple silicon substrate. Modifications to the terraced oxide structure are proposed to remove oxidation effects of the alternate channel materials. The extracted work function of TiN with various thicknesses on HfSiO is found to be in agreement with that of TiN on a silicon substrate. X-ray and ultraviolet photoelectron spectroscopy are used to observe the interface electronic states at the GaN (0001) and Al2O3, HfO2 and GaON dielectric interfaces. The GaN is cleaned using aqueous HCl prior to thermal oxidation to form GaON and atomic layer deposition of Al2O3 and HfO2. This was followed by a post deposition anneal. The GaN/HfO2 and GaN/Al2O3 interfaces exhibited dipoles of 1.6 eV and 0.4 eV +/- 0.2 eV, respectively. It is determined that the formation of an interfacial layer at the GaN/HfO2 interface is the primary cause of the larger dipole. Due to the knowledge of the formation of an interfacial GaOx or GaON layer during atomic layer deposition of HfO2, a better understanding of the GaN/GaON interface is needed. To accomplish this task, the interface electronic states at the GaN(0001) and GaON interface are observed using X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). XPS and UPS analysis of the GaN/GaON interface resulted in the calculation of a -2.7 eV +/- 0.2 eV dipole assuming that the core level shifts are only representative of the GaN band bending at the interface. If it is assumed that the core level shifts are only due to the oxidation of GaN, then the exhibited dipole at the GaN/GaON interface is -1.8 eV +/- 0.2 eV. Results indicate that the observed dipole is primarily caused by the polarization of the GaN. A theoretical approach is taken to provide a more complete understanding of the underlying formation mechanisms of a GaON interfacial layer during atomic layer deposition of HfO2. First, density functional theory is used to calculate the interactions of oxygen and water with the Ga-face of GaN clusters. The GaN clusters could be used as testbeds for the actual Ga-face on GaN crystals of importance in electronics. The results reveal that the local spin plays an important role in these interactions. It is found that the most stable interactions of O2 and the GaN clusters results in the complete dissociation of the O2 molecule to form two Ga-O-Ga bonds, while the most stable interactions between a H2O molecule and the GaN clusters are the complete dissociation of one of the O-H bonds to form a Ga-O-H bond and a Ga-H bond. Second, density functional theory is used to calculate the interaction of the reactants used to deposit HfO2 and Al2O3 during atomic layer deposition with hydrolyzed Ga-face GaN clusters. The results suggest that while further research is needed in this area to grasp a better understanding of the interactions of Trimethylaluminum (TMA) or Tertrakis(EthylMethylAmino)Hafnium (TEMAH) with hydrolyzed GaN clusters, it is found that a Ga-N(CH3)(CH2CH3) bond can form during the deposition of HfO2 using ALD and TEMAH as the reactant without breaking the Hf-N bond. The formation of a Ga-N(CH3)(CH2CH3) bond is significant because with the introduction of water into the system, the methyl and ethylmethyl groups may react to form a Ga-N-O bond which is believed to be the interfacial oxide found during deposition of HfO2 using ALD on GaN. No Ga-C bond structure formed in any fully optimized stable structure when analyzing the interaction of TMA with hydrolyzed GaN.

Thesis (Ph.D.) -- McMaster University, 2002. / Adviser: Anthony Petric. Includes bibliographical referernces. Also available via World Wide Web.

Thesis (Ph.D.) -- McMaster University, 2002. / Adviser: Anthony Petric. Includes bibliographical referernces. Also available via World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Jack C. Lee. Vita. Includes bibliographical references. Also available from UMI.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (M.S.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.