(651f) Device Integration of the Ets-4 Quantum Wire Arrays

Authors: 
Yilmaz, B., CAMMP/Northeastern University
Warzywoda, J., Northeastern University
Sacco, Jr., A., Northeastern University


Conventional nano-manufacturing techniques have severe size and geometry limitations in preparation of purely one-dimensional systems (i.e., quantum wires). Hence, quantum wire fabrication still presents a problem of considerable technical complexity and thus elevated cost. Preparation of ordered, aligned arrays of quantum wires that would be required for most prospective applications is considered even more challenging. There are also potential problems in device integration with products obtained via conventional fabrication techniques. In order to overcome these obstacles, novel strategies for the fabrication of quantum wire arrays are necessary. ETS-4 is a crystalline titanosilicate material. In its crystalline framework [TiO6] octahedra are linked to form linear ?Ti ? O ? Ti ? O ? Ti? chains, which are isolated from each other by an insulating siliceous matrix made of [SiO4] tetrahedra. Therefore ETS-4 crystals are essentially arrays of quantum wires. We have previously reported the detailed investigation of the optical band gap transition in ETS-4. The blue shift of the optical band gap was demonstrated for ETS-4 when compared to bulk titania, which can be considered as the verification of the quantum confinement of the titania chains in ETS-4. These monatomic titania chains (quantum wires) are the thinnest wires that can be hypothesized. An investigation was undertaken to explore the feasibility of integrating the ETS-4 quantum wire arrays into micro devices. A fabrication methodology was developed to individually address an ETS-4 crystal and incorporate it into a device. The major stages of this fabrication methodology include attachment of the crystal onto substrate, special mask design, photolithography, metal deposition via thermal evaporation and lift-off. Utilizing this methodology a novel device with an ETS-4 quantum wire array component was prepared.