Metal-oxide-semiconductor field effect nanostructural spin lattice devices

This dissertation explored and developed technologies for silicon based spin lattice devices. Spin lattices are artificial electron spin systems with a periodic structure having one to a few electrons at each site. They are expected to have various magnetic and even superconducting properties when structured at an optimal scale with a specific number ѵ of electrons. Silicon turns out to be a very good material choice in realizing spin lattices. A metal-oxide-semi conductor field-effect nanostructure (MOSFENS) device, which is closely related to a MOS transistor but with a nanostructured oxide-semi conductor interface, can define the spin lattices potential at the interface and alter the occupation ѵ with the gate electrode potential to change the magnetic phase. The MOSFENS spin lattices engineering challenge addressed in this work has come from the practical difficulty of process integration in modifying a transistor fabrication process to accommodate the interface patterning requirements. Two distinct design choices for the fabrication sequences that create the nanostructure have been examined. Patterning the silicon surface before the MOS gate stack layers gives a "nanostructure first" process, and patterning the interface after forming the gate stack gives a "nanostructure last process." Both processes take advantage of a nano-LOCOS (nano-local oxidation of silicon) invention developed in this work. The nano-LOCOS process plays a central role in defining a clean, sharp confining potential for the spin lattice electrons.