Award Date


Degree Type


Degree Name

Master of Science (MS)


Electrical and Computer Engineering

Number of Pages



A theoretical formulation for carrier current across hetero-interface in heterostructure semiconductor devices is presented using tunneling as the phenomenon. An analytical expression for the transmission coefficient as a function of energy using the Airy's function and exponential solutions to Schroedinger's equation for a linear potential variation is used in the calculations. This thesis addresses two theoretical problems: physics and modeling of gate current dependance on gate voltage in a heterostructure insulated gated field effect transistor (HIGFET) and, oscillations in the current-voltage characteristics of a double heterostructure bipolar transistor (DHBT); For HIGFETs, two components of tunneling currents, one from the decay of the quasi-bound resonant states in the accumulation well and the other from the tunneling electrons with kinetic energy above the bulk energy level, were considered. Moreover, the possibility of hot electrons is addressed. The reason for the large discrepancies between the experimental values and the theoretical values reported in earlier literature is attributed mainly due to the exclusion of the hot electron mechanism and the neglect of the contribution to current from the decay of the resonant states in the accumulation well; The origin of oscillations in the collector saturation current of a DHBT (with a set back layer) is investigated theoretically. Energy band balance was performed at the base-set back layer and set back layer-collector junctions to determine the distribution of the output voltage, {dollar}V\sb{BC}{dollar}, at these junctions and the conduction band edge profile using degenerate statistics. Theoretical results are in excellent agreement with the experimental results with {dollar}V\sb{BC}{dollar}'s at which the first two peaks of the {dollar}I\sb{D,sat}{dollar} occur matching closely. (Abstract shortened by UMI.).


Devices; Heterostructure; Phenomenon; Tunneling

Controlled Subject

Electrical engineering

File Format


File Size

1320.96 KB

Degree Grantor

University of Nevada, Las Vegas




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