{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/24496"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/24496","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Scanning tunneling microscopy and spectroscopy of nanometer scale metallic features on silicon surfaces","abstract":"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.","abstract_html":"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.","abstract_has_math":false,"creators":["Ye, Wei"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science & Engr","degree_department":null,"school":null,"contributors":["Lyding, Joseph W.","Abelson, John R.","Girolami, Gregory S.","Rockett, Angus A.","Shim, Moonsub"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-25T14:26:28Z","date_published":"2011-05-25T14:26:28Z","updated_at":"2026-07-22T22:25:23Z","subjects":["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"],"languages":["en"],"rights":["Copyright 2011 Wei Ye"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/24496","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lyding, Joseph W.","Abelson, John R.","Girolami, Gregory S.","Rockett, Angus A.","Shim, Moonsub"]},{"key":"dc:creator","label":"Author","values":["Ye, Wei"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-25T14:26:28Z","2013-05-26T10:00:20Z","2011-05"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science & Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["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"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2011 Wei Ye"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/24496"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["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"]},{"key":"dc:title","label":"Title","values":["Scanning tunneling microscopy and spectroscopy of nanometer scale metallic features on silicon surfaces"]}]}],"canonical_facts":{"dc:contributor":["Lyding, Joseph W.","Abelson, John R.","Girolami, Gregory S.","Rockett, Angus A.","Shim, Moonsub"],"dc:creator":["Ye, Wei"],"dc:date":["2011-05-25T14:26:28Z","2013-05-26T10:00:20Z","2011-05"],"dc:description":["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"],"dc:identifier":["http://hdl.handle.net/2142/24496"],"dc:language":["en"],"dc:rights":["Copyright 2011 Wei Ye"],"dc:subject":["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"],"dc:title":["Scanning tunneling microscopy and spectroscopy of nanometer scale metallic features on silicon surfaces"],"thesis:degree_discipline":["Materials Science & Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:23Z"}