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oai:www.ideals.illinois.edu:2142/24496 2023-07-10 col_2142_5131 col_2142_13836 com_2142_5130 com_2142_13835 com_2142_234

Lyding, Joseph W. Lyding, Joseph W. Abelson, John R. Girolami, Gregory S. Rockett, Angus A. Shim, Moonsub Ye, Wei 2011-05-25T14:26:28Z 2011-05-25T14:26:28Z 2013-05-26T10:00:20Z 2011-05-25T14:26:28Z 2011-05 Nanometer scale metals are of great interest due to their potential applications in the future of molecular/atomic scale devices. For example, nanometer scale metal contacts on semiconducting single-walled carbon nanotubes (SWNTs) can determine the transport performance of SWNT based field effect transistors (FETs). In this thesis, I have used an ultrahigh vacuum (UHV) scanning tunneling microscope (STM) to fabricate nanometer scale metallic features on the Si(100)-2×1:H surface and form nanoscale metal contacts on the SWNTs. Scanning tunneling spectroscopy (STS) is used to study the electronic properties of the metallic features and the nano-contacts. Two kinds of metallic features are studied. First, an unpaired dangling bond (DB) can be formed on Si(100)-2×1:H surface using an STM nanolithography method. The unpaired DB, which shows metallic behavior, can perturb its surroundings electronically up to ~1.9 nm by introducing a near-midgap state in the local density of states (LDOS) of neighboring Si atoms. The decay length of the DB-states of an unpaired DB wire can be ~2.5 nm along the dimer row direction. The perturbation of an unpaired DB to an adjacent paired DB is also demonstrated. Second, sub-5 nm HfB2 metals can be direct written on the Si surface using STM electron beam induced deposition (STM-EBID). Nanoscale contacts between HfB2 metal and semiconducting SWNTs can be formed by direct writing HfB2 onto a SWNT or by manipulating a SWNT with the STM tip onto HfB2. STS studies indicate a strong Schottky barrier formed at the HfB2/SWNT interface, which induces metallicity in the SWNT. Metal induced gap states (MIGS) are also observed adjacent to the contact. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-04-20T00:14:19Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Ye_Wei.doc: 9410560 bytes, checksum: bd08d7eff23533c96cdce7cda15f9783 (MD5) Ye_Wei.pdf: 7127662 bytes, checksum: 6e480d46e050f01ed03668bdef5a2843 (MD5) Made available in DSpace on 2011-05-25T14:26:28Z (GMT). No. of bitstreams: 3 Ye_Wei.pdf: 7127705 bytes, checksum: 5468cc24f81922a15d6da27fac126ab0 (MD5) license.txt: 4053 bytes, checksum: ccaca33cadcdfd404e2c55995b296327 (MD5) Ye_Wei.doc: 9410560 bytes, checksum: bd08d7eff23533c96cdce7cda15f9783 (MD5) Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2011-05-25T14:30:04Z Item is restricted until 2013-05-25T14:29:35Z Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2013-05-26T10:00:20Z Item was in collections: University of Illinois Dissertations and Theses (ID: 204) Dissertations and Theses - Materials Science and Engineering (ID: 649) No. of bitstreams: 3 Ye_Wei.pdf: 7127705 bytes, checksum: 5468cc24f81922a15d6da27fac126ab0 (MD5) license.txt: 4053 bytes, checksum: ccaca33cadcdfd404e2c55995b296327 (MD5) Ye_Wei.doc: 9410560 bytes, checksum: bd08d7eff23533c96cdce7cda15f9783 (MD5) Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2013-05-26T10:00:20Z http://hdl.handle.net/2142/24496 en Copyright 2011 Wei Ye Scanning tunneling microscopy Scanning tunneling spectroscopy scanning tunneling microscope - electron beam induced deposition (STM-EBID) Metal induced gap states (MIGS) Dangling bond Si(100) Hydrogen passivation Single-walled carbon nanotube Nano-contact Direct write Nanofabrication Schottky Barrier Scanning tunneling microscopy and spectroscopy of nanometer scale metallic features on silicon surfaces 1919 Materials Science & Engineerng Materials Science & Engr 0130 University of Illinois at Urbana-Champaign Dissertation Ph.D. PHD:Materials Sci & Engr -UIUC 10KS0130PHD