Dissertation (Ph.D.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 175-176). Also available via the Internet.

Thesis (M.S.)--Rochester Institute of Technology, 1994. / Typescript. Includes bibliographical references (leaves 112-117).

Thesis (M.App.Sc.) - Carleton University, 2002. / Includes bibliographical references (p. 147-151). Also available in electronic format on the Internet.

Thesis (Ph. D.)--Lehigh University, 1999. / Includes vita. Bibliography: leaves 91-96.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 64-65). Also available via the Internet.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 45).

Bipolar transistors employing an MIS junction for the emitter exhibit the very desirable properties of high operating frequency and/or high common emitter gains. The topic of this thesis is to investigate the usefulness of the MIS bipolar transistor in real applications. The experimental results show two possible limitations of the devices. The principal limitation is the inability of these devices to withstand moderate temperature stressing. The second limitation is the relatively high emitter series resistance. The principal degradation mode of these devices under temperature stressing is suggested to be the reduction of the thin insulating oxide. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

A one-dimensional analytical model in the Ebers-Moll formulation of a graded base double heterojunction bipolar transistor (DHBT) is developed and used to examine the effects of base grading, the emitter-base barrier and the base-collector barrier on the d.c. current gain, offset voltage and the high frequency performance of a N — Al[formula omitted]Ga₁[formula omitted]As/p — Al[formula omitted]Ga₁[formula omitted]As/N — Al[formula omitted]Ga₁[formula omitted]As DHBTs. Recombination processes considered in the space charge regions and the neutral regions are: Shockley-Read-Hall, radiative and Auger. The trade-off between base-grading, which reduces the base current, and the neutral base recombination, which is brought about by varying the aluminium the junctions, results in an optimum aluminium mole fraction profile regarding the d.c. current gain. For high frequency performance, a similar trade-off to that of the d.c. situation exists. In this case, the important manifestation of the increased collector-base barrier height is an increase in the base transit time. The aluminium mole fraction profile which optimises the unity gain cut-off frequency, f[formula omitted], and the unity power gain cut-off frequency, f[formula omitted], is established. DHBTs which are symmetrical, both in aluminium mole fraction and doping concentration profiles, are shown to have low common-emitter offset voltages, V[formula omitted],[formula omitted]. Base-grading reduces V[formula omitted],[formula omitted] in devices in which the difference between the emitter and collector aluminium mole fraction is < 0.1; otherwise, V[formula omitted],[formula omitted] increases as base-grading increases. The model is also used to examine the performance of a N-Al[formula omitted]Ga₁[formula omitted]As/p-In[formula omitted]Ga₁[formula omitted]As/N-Al[formula omitted]Ga₁[formula omitted]As DHBT. It is shown that radiative and Auger recombination limit the d.c. current gain in this device. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

An investigation into various methods of calculation of the high frequency performance parameter f[formula omitted] for microwave heterojunction bipolar transistors is presented. Two high frequency representations of the device are developed: equivalent circuits consisting entirely of lumped circuit elements, and a two-port network based on drift-diffusion equations. Proper account is taken in these representations of the phase delay associated with carrier transit time through the base and base-collector space charge region. Also included are the charging time effects due to the various parasitic circuit elements associated with actual devices. A single-sided isolated structure is used in simulations and it is found that both representations yield remarkably similar characteristics for the behavior of unilateral gain U with frequency. For devices in which the dominant factors limiting high frequency performance are the parasitic resistances and capacitances, it is found that U rolls off at 6 dB/octave through the region where U = 1 and the values predicted for f[formula omitted] via these two methods, as well as via the widely-used analytical expression involving f[formula omitted] and (R[formula omitted]C[formula omitted])[formula omitted], are in agreement. However, when the periods of the oscillations are on the order of the carrier transit times, and the device parasitics are sufficiently low so as to not limit performance, resonance effects occur in U in the region where U = 1 and the prediction of f[formula omitted] obtained via the two equivalent circuit approaches deviates markedly from the predictions of the analytical expression. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate