Ultrafine ZnO nanowire electronic device arrays fabricated by selective metal-organic chemical vapor deposition

The integrated fabrication of ultrafine ZnO nanowire devices using selective and lateral growth of ZnO nanowires on amorphous substrates was demonstrated. Two types of Au patterns were formed on degenerately doped n-type silicon (100) substrates coated with a 1-μm thick SiO₂amorphous layer by using electron-beam lithography. Ti/Au metal electrodes were deposited on the ends of the nanowires by electron-beam lithography, evaporation of 100-Å-thick Ti and Au contacts, and lift-off processes. The Au patterns were used as alignment markers to form the metal electrodes at the ends of nanowires. Ti/Au source electrodes were deposited on the initial nucleation sites and the drain electrodes were created on the ends of the nanowires. The fabrication process resulted in the formation of nanowire bridges between metal electrode pairs with high connection rates greater than 90%.