| The III-V nitrides, gallium nitride, GaN, indium nitride, InN, and aluminum nitride, AlN, have found applications in several areas of the semiconductor industry in the last five years. The nitride's large band gaps have made possible for the first time bright and efficient blue-green LEDs and blue-violet lasers. During this short time frame, these optoelectronic devices have gone from the research lab to commercial success. Another promising area for the nitrides is high power, high frequency electronics. The unique properties of AlGaN/GaN interface allow very high current densities to be obtained while at the same time allowing the devices to operate at high voltages. These properties combined with the superior thermal properties of the nitrides and its substrate (SiC) allow these devices to be operated at very high power densities. For these reasons, it is important to understand the electron transport properties of these materials as well as the physics of their devices.; This dissertation studies the transport properties of the III-V nitrides as a function of the temperature of the material and its doping concentration. This is achieved through the use of a semi-classical self-consistent ensemble Monte Carlo simulation. It is found that the nitrides maintain high average electron velocities even when the temperature is increased to 700 K and doping concentrations to 1019 cm-3, especially when compared to more common compound semiconductors such as GaAs.; Next, the transport results are used to develop analytical models of the AlGaN/GaN polarization induced high electron mobility transistor. First, the properties of the two-dimensional electron gas are examined and modeled. Then, several techniques are used to develop different transistor models. These analytical models use relatively few parameters, most of which can be measured experimentally. The model predictions compare well with data from fabricated AlGaN/GaN transistors. When the simulated Monte Carlo transport data is used in the transistor models, it is predicted that future devices may operate with drain currents 40% higher than current devices. |
