Amorphous multi-component metals as electrode materials

Type
Thesis
Year of Publication
2010
Authors
William Cowell
Date Published
Jan. 1, 2010
Publisher
Oregon State University
Abstract

The objective of this thesis is to provide an initial demonstration of two-terminal and three-terminal electronic devices employing amorphous multi-component metallic film (AMMF) electrodes. Such a demonstration is successfully achieved in the fabrication of metal-insulator-metal (MIM) diode and hot electron transistor (HETs) structures employing ZrCuAlNi AMMF electrodes. The ultra-smooth surface morphology resulting from the Zr-CuAlNi film's amorphous nature is investigated via atomic force microscopy, x-ray diffraction, and electron diffraction. The work function characteristics of a ZrCuAlNi AMMF are investigated using Kelvin-probe analysis. Resistivity of the ZrCuAlNi AMMFs is characterized using four-point probe measurements. The resistances of patterned ZrCuAlNi AMMF electrodes are measured to provide insight into electrode resistance variability caused by film and contact processing. Electrical measurements of two-terminal MIM diodes, employing at least one ZrCuAlNi AMMF electrode and a variety of dielectrics, are undertaken in order to study the effects of tunneling potential barrier height, dielectric thickness, and dielectric constant on MIM diode current-voltage characteristics. Energy band analysis, electrical characterization, and mathematical simulations elucidate the feasibility of MIM diodes fabricated with ZrCuAlNi AMMF electrodes. A three-terminal HET structure employing ZrCuAlNi AMMF electrodes is electrically characterized, after which an energy band analysis is undertaken to provide insight into observed current-voltage characteristics. The maximum frequency of operation, f[subscript max], is calculated for a HET employing ZrCuAlNi electrodes.