Growth and characterization of group III-nitride power transistors, power rectifiers and solar-blind detectors by metalorganic chemical vapor deposition

This dissertation describes an{09}investigation of the growth of aluminum gallium nitride (Al_xGa_1−xN, 0 ≤ x ≤ 1) semiconductor materials by metalorganic chemical vapor deposition (MOCVD) for Schottky diode (SD) power rectifier, p-i-n power rectifier, heterojunction bipolar transistor (HBT), heterojunction field-effect transistor (HFET), and solar-blind detector (SBD) device applications. Chapter 1 reviews the main properties of group III-nitride material system as well as the current status of nitride-based growth and device research. Chapter 2 describes how the MOCVD growth technique may be employed to obtain high-quality nitride-based material. In this discussion, the different methods to improve material quality as well as the procedures to track the improvements are developed. Chapter 3 presents the characterization techniques used to evaluate the electrical, physical and optical quality of group III-nitride materials. Particular attention is given to x-ray diffraction, photoluminescence, cathodoluminescence, and Hall effect measurement, because these characterization methods give a clear and fast indication of material quality. Chapter 4 discusses the theoretical calculations that are necessary to understand the characteristics and behavior of group III-nitride materials. The results of the calculations are used for MEDICI® simulation of AlGaN/GaN HBTs and constitute a guidance for the design of advanced heterostructures. Chapter 5 focuses on the growth and characterization of power devices. This chapter is divided into three sections dedicated to power rectifiers, power bipolar transistors and power HFETs. Chapter 6 is devoted to the growth and characterization of solar-blind photodetectors. The first part of this section presents a discussion of p-i-n SBDs, while the second one deals with solar-blind metal-semiconductor-metal (MSM) photodiodes. Finally, this dissertation concludes with Chapter 7 that summarizes the work, as well as discusses some potential future research, which could extend the results derived from this work.