Novel device applications employing LPCVD tungsten

By combining the selective nature of the LPCVD tungsten deposition method with micromachining and laser processing techniques, several microelectronic devices have been developed. These include ultrathin tungsten filaments, tungsten loops, a silicon-to-tungsten converted, laser-recrystallized, field-effect transistor on insulator, and tungsten cladding of laser-written polysilicon interconnects. The filaments are used to investigate one- and/or two-dimensional fundamental physical effects, such as localization or electron-electron interaction behavior at cryogenic temperatures. The loops are used to investigate the Aharanov-Bohm effect which produces an oscillatory magnetoresistance pattern due to phase differences of the electron wavefunctions along the two paths of the loops. The transistor promises applications in high-density, radiation hardened VLSI circuits. The low resistance, laser-written interconnect process promises applications in the customization of integrated circuits