ECE Faculty Candidate
Friday **Special day, time, and location** May 18th 11 - 11:50am KEC 1007 John F. Conley, Jr. Sharp Labs of America Camas, WA Nanotechnology: Field Emission Induced UV Electroluminescence of Carbon Nanotubes Coated with Atomic Layer Deposited ZnO and Directed Integration of ZnO Nanobridge Devices The seminar will begin with a brief introduction to nanotechnology followed by a description of two recent projects. In the first, atomic layer deposition (ALD) was used to coat carbon nanotubes (CNTs) with a thin film of ZnO. ALD is a highly conformal deposition technique in which films are deposited on a surface one monolayer at a time. CNTs are well known to have excellent field emission properties. ZnO is a versatile wide bandgap transparent semiconductor material with unique piezoelectric, UV photo luminescent (PL), gas sensing, and field emission properties that hold much promise for nanotech applications. Annealing of the ZnO coated CNTs led to the formation of ZnO nanoparticles on the surface of the CNTs. These unique structures were investigated with a combination of field emission, electroluminescence (EL), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) measurements. It was found that ZnO nanoparticle coated CNTs exhibited improved field emission characteristics and a UV EL peak at 382 nm that was not detectable in uncoated CNTs. This work demonstrates the utility of ALD for surface modification of nanostructures The second part of the seminar will discuss the directed assembly and integration of ZnO nanobridges into working devices on silicon-on-insulator substrates. The work is unique in that the most widely used methods of nanowire (NW) growth (vapor-liquid-solid using metal catalysts such as Au) and NW integration (the "pick and place" method in which NWs are grown on one substrate, harvested into solution, and then deposited randomly onto a device subsrate) were avoided. Instead, ZnO NWs were grown selectively via a vapor-solid method using a patterned ZnO thin-film seed layer that was deposited on Si trench sidewalls via ALD. ZnO NWs grew to span the trench and self-terminated on the opposing surface, effectively forming electrically accessible ZnO horizontal nanobridge devices. Vertical bridge devices were also constructed using undercut islands. Directly grown horizontal ZnO nanobridge devices were operated as gas and UV sensors, demonstrating that this method represents a promising step towards practical large-scale integration of nanodevices into Si microelectronics. Biography: John F. Conley, Jr. John Conley earned his B.S. in Electrical Engineering in 1991 and Ph.D. in Engineering Science and Mechanics in 1995 from The Pennsylvania State University where he won a 1996 Xerox Prize for his Ph.D. dissertation. Dr. Conley was at Dynamics Research Corporation from 1995 to 2000 and at the Jet Propulsion Laboratory from 2000-2001, where he received an achievement award. In 2001, Dr. Conley became a senior member of the technical staff at Sharp Laboratories of America, where his research interests included atomic layer deposition, high- dielectrics, and optoelectronic/sensing device applications of nano-structured materials. In 2002-03, while working at SLA, he served as an adjunct professor at the Vancouver campus of Washington State University. Since 2005, he has been the leader of the Novel Materials and Devices Group at SLA and has led the MEMS biosensor and silicon nanowire projects. Dr. Conley has authored or co-authored over 90 technical papers (including several invited) and over 90 conference presentations. He holds ten U.S. patents. He has recently presented tutorial short courses on high-k dielectrics at two international conferences and was the lead co-editor of two special issues of IEEE Transactions on Device and Material Reliability. He has also served on the technical and management committees of the IRPS, the SOI Conference, and the Nuclear and Space Radiation Effects Conference, and was technical program chair of the 2000 IEEE Microelectronics Reliability and Qualification Workshop. In 2006, Dr. Conley served as the general program chair of the IEEE International Integrated Reliability Workshop.
_______________________________________________ Colloquium mailing list [email protected] https://secure.engr.oregonstate.edu/mailman/listinfo/colloquium
