This NIRT proposal focuses on development of innovative processes for fabrication of quantum and molecular devices use the novel horizontal 1-D AAO array nanotemplate. The research is divided into four main thrusts. In the first thrust, the PIs will refine the process for improving the 1-D horizontal AAO nanostructure, reduce the pore size of the 1-D nanotemplate down to 1 nm using atomic layer deposition, and grow a 1-D array of carbon nanotubes and nanowires aligned horizontally on the silicon substrate. In the second thrust, the PIs will fabricate single-electron transistor (SET) arrays based on the horizontal 1-D array of nanowires. In the third thrust, they will utilize the horizontal 1-D nanpore array for fabrication of in-wire molecular junction arrays and use the horizontal 1-D array of CNTs for fabrication of nanoscale electrodes to isolate single molecules. In the fourth thrust, they will characterize the horizontal 1-D array of nanopores and individual in-wire nanodevices using conductive AFM.
The intellectual merit of the proposed activities is to advance the self-assembled AAO template technique toward high-level and large-scale integration of devices compatible with the mainstream planar process technology.
The broader impacts of the proposed work include significant advancement of critical bottom-up self-assembly processes, enhancement of multidisciplinary research, education and training of tomorrows scientists and engineers in nanotechnology. The research proposed here will lay a foundation for high-density and large-scale integration of nanotube and nanowire-based quantum and molecular devices. This unique horizontal 1-D structure will find broad applications in basic understanding of transport of molecules, new fabrication procedures, and practical industrial applications. The proposed education activities will enhance the involvement of graduate students in the multidisciplinary environment and also impact Appalachian communities (economically depressed group) through focused education outreach.
Intellectual Merit The goal of the project is to advance the self-assembled one-dimensional anodic aluminum oxide (AAO) array template technique toward high-level and large-scale integration of devices compatible with the mainstream planar process technology. We successfully fabricated an AAO template with a one-dimensional (1-D) array of nanopores horizontally aligned on a silicon substrate. This novel structure provides a great potential for fabrication of molecular and electronic device compatible with the planar processing technology. We developed 1-D molecular junction arrays based on 1-D nanopore AAO array templates, and measured the charge transport behavior of 1-Dedecanemonothiol and 1, 4 Benzenedithiol junctions. Nanoscale multilayer edge molecular electrode (MEME) for molecular conduction was fabricated. A novel approach Junctions were successfully fabricated with low leakage current (10 pA@ 100mV bias). MEME electrodes with molecules do exhibit larger current. We developed a pre-patterning of the aluminum surface technique for the creation of nanoporous AAO templates with controllable aspect ratio, inter-pore spacing and pore diameter. We successfully developed a conductive atomic force microscopy (cAFM) technique, atomic force photovoltaic microscopy (AFPM). The image of a transparent conductive line written with a Ga FIB beam in In2O3 was obtained by the conductive AFM. This research was featured on the cover of the February 9, 2009 issue of Advanced Materials. Broader Impacts The project enhanced the involvement of graduate and undergraduate students in the multidisciplinary environment and also impact Appalachian communities (economically depressed group) through K-12 outreach. Dr. Bruce Hinds developed lecture and laboratory workshops to teach students at multiple education levels (high school, undergraduate and graduate) about the tools of microfabrication. The Research Experience for Undergraduates (REU) program at Northwestern University directed by Dr. Mark Hersam hosted ~120 undergraduates (including ~60 female students and ~60 underrepresented minority students) for a 9 week intensive summer research experience. REU undergraduate students at University of Kentucky supervised by Dr. Zhi David Chen also have extensive training in nanoscale fabrication in Cleanroom. These activities helped attracting underrepresented undergraduate students to science and engineering. Dr. Zhi David Chen participated in the Rogers Scholar Program organized by the Center for Rural Development, Somerset, KY, for high school students from Eastern and Southern Kentucky communities (Appalachian area). On May 22, 2009, Dr. Chen, with Drs. Chaoyuan Mary Liu and Dirk Schlingmann at Eastern Kentucky University, Richmond, KY, outreached to students at North Laurel High School, London, KY. Dr. Chen presented "Computer Chips: A World of Nano-Scale Electronics". Students were very excited about the presentation and understanding much better why the industry can produce a new generation of computer chips in every three years.
