Archive | 2021
Integration of oxide-metal and nitride-metal vertically aligned nanocomposites on silicon toward device applications
Abstract
Devices that can\nprocess more information in reduced dimensions are essential for an\nincreasingly information- and efficiency-driven future. To this end,\nnanocomposites are promising due\nto their inherent multifunctional properties and special behavior at the nanoscale.\nVertically aligned nanocomposites (VANs) are particularly interesting because\nof their ability to self-assemble into anisotropic nanostructures and high density\nof heterointerfaces – characteristics which introduce unique functionalities\nand offer exciting new avenues for device applications. However, a vast\nmajority of VAN systems are currently fabricated on single-crystal oxide substrates,\nwhich may be cost-prohibitive at large scales and are generally incompatible\nwith the prevalent device fabrication techniques. Thus, integration of VAN thin\nfilms on silicon becomes a critical step toward implementing VANs in a\nwell-established semiconductor manufacturing industry. \n\nIn this dissertation, the\nviability of oxide-metal and nitride-metal VAN thin films integrated on silicon\nsubstrates has been demonstrated through a set of unique buffer layer designs. For\nthe first three systems presented in this dissertation, namely, LaSrFeO4-Fe,\nBaTiO3-Au, and BaTiO3-Fe, microstructural and physical property\n(i.e. electrical, magnetic, and optical) analyses confirm their successful epitaxial\ngrowth on silicon, with only minor differences compared to their counterparts\ngrown on single-crystal oxide substrates. For the fourth system, a new and\nrobust TiN-Fe VAN has been proposed and demonstrated. The new TiN-Fe VAN system\non Si exhibits superior magnetic properties and unusual optical properties. With\nfurther growth optimization and/or patterning techniques, VAN thin film integration\non silicon presents itself as a feasible and cost-effective approach to\ndesigning electronic, spintronic, photonic, and sensing devices.