AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Thursday Sessions
       Session NS-ThA

Paper NS-ThA10
Current-Induced Local Oxidation: Mechanism, Quantum-Size Effects, and Applications

Thursday, November 5, 1998, 5:00 pm, Room 321/322/323

Session: Nanoscale Manipulation and Chemical Modification
Presenter: R. Martel, IBM T.J. Watson Research Center
Authors: R. Martel, IBM T.J. Watson Research Center
T. Schmidt, IBM T.J. Watson Research Center
Ph. Avouris, IBM T.J. Watson Research Center
Correspondent: Click to Email
A novel method is introduced for locally oxidizing thin metal films with nanometer-scale resolution. Simply by subjecting Ti and Nb films in air to local current densities of 10@super 7@ A/cm@super 2@, metal-oxide tunneling barriers of 10-50 nm width can be fabricated in a self-limiting fashion. The high spatial resolution of the process results from its strongly non-linear dependence on the current density. Our experiments suggest that the oxidation involves current-induced atomic rearrangements and local heating. At the final stages of the barrier formation, when only atomic-scale channels remain unoxidized, the oxidation rate decreases drastically while the conductance drops in steps of about 2e@super 2@/h. This behavior gives evidence of conductance quantization and a superior stability of such metallic nanowires against current-induced forces compared with the bulk metal. This current induced local oxidation (CILO) process can be used in nanofabrication. Single electron transistor structures exemplifying Coulomb staircases at room temperature were fabricated in this manner.