Advancements in the gallium arsenide/nickel aluminum material system and its potential for device applications: Progress towards the realization of a metal base transistor

The concept of a metal base transistor is not a new one. In 1960, Carver A. Mead published a paper proposing a tunnel-emission amplifier comprised of metal-insulator-metal-insulator-metal structure in which the two insulator layers are thin barriers that produce tunnel-effect transmission of electrons between the metal layers. The middle metal layer would be thin with respect to the electronic mean free path in it. This structure would be capable of power gain in an analogous way to a conventional bipolar transistor.;However, the realization of such a device was hampered by two problems. First, the large quantum mechanical reflection of electrons at the collector barrier of the device prohibited a large gain-a device physics problem. Second, the chosen material system, aluminum metal layers and oxidized aluminum layers (Al/Al;In this thesis a different approach to realizing a practical metal base hot electron transistor will be investigated. In this approach, Molecular Beam Epitaxy (MBE) will be used to grow structures consisting of both III-V (GaAs based) semiconductors and single-crystal metals composed of NiAl. The advantages to this new approach will be discussed with respect to overcoming both of the problems mentioned above. A brief review of hot electron transistors will be provided. A discussion of hot electron transistors will emphasize the device physics relevant to overcoming the problems associated with a simple semiconductor hot electron transistor that is structurally very similar to the first metal/oxide transistor proposed by Mead. The later part of this thesis will focus on the material science related to the realization of a metal base transistor--specifically, how NiAl and related alloys, can be successfully grown on lattice mismatched III-V semiconductor substrates and employed in hot electron structures. It is the advancements in materials research that will ultimately be responsible for the success in realizing a metal base transistor since the structure of the transistor will largely be dictated by the material system used to construct the device.