{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21184"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21184","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Thermal and low-energy ion doping of silicon(001) during molecular beam epitaxy: Dopant incorporation kinetics and mechanisms","abstract":"Thermal and accelerated-ion doping, with In and Sb, during Si(001) molecular-beam epitaxy were investigated as a function of growth temperature T$\\sb{\\rm s}$ (500-1050$\\sp\\circ$C), dopant energy E$\\sb{\\rm d}$ (thermal-500 eV), and Si deposition rate R$\\sb{\\rm Si}$ (0.18-4.7 $\\mu$m h$\\sp{-1}).$ Surface segregation during thermal doping led to severe profile broadening and low temperature-dependent incorporation probabilities $\\sigma\\sb{\\rm d,th}.$ On the other hand, $\\sigma\\sb{\\rm d}$+ for In-ions at energies E$\\sb{\\rm In}$+ $\\ge$ 200 eV or Sb-ions accelerated by potentials V$\\sb{\\rm Sb}$+ $\\ge$ 300 V was essentially unity up to T$\\sb{\\rm s}\\sim850$-900$\\sp\\circ$C. At lower ion energies, $\\sigma\\sb{\\rm d}$+ was temperature and energy dependent, but was still much higher than $\\sigma\\sb{\\rm d,th}.$ Abrupt tailored depth profiles were easily obtained by controlling the ion current; layers $\\delta$-doped with a 250 V Sb-ion beam were $\\le$2 nm wide.","abstract_html":"Thermal and accelerated-ion doping, with In and Sb, during Si(001) molecular-beam epitaxy were investigated as a function of growth temperature T$\\sb{\\rm s}$ (500-1050$\\sp\\circ$C), dopant energy E$\\sb{\\rm d}$ (thermal-500 eV), and Si deposition rate R$\\sb{\\rm Si}$ (0.18-4.7 <span class=\"etd-inline-math\">&mu;</span>m h$\\sp{-1}).$ Surface segregation during thermal doping led to severe profile broadening and low temperature-dependent incorporation probabilities <span class=\"etd-inline-math\">&sigma;\\sb{\\rm d,th}.</span> On the other hand, <span class=\"etd-inline-math\">&sigma;\\sb{\\rm d}</span>+ for In-ions at energies E$\\sb{\\rm In}$+ $\\ge$ 200 eV or Sb-ions accelerated by potentials V$\\sb{\\rm Sb}$+ $\\ge$ 300 V was essentially unity up to T$\\sb{\\rm s}\\sim850$-900$\\sp\\circ$C. At lower ion energies, <span class=\"etd-inline-math\">&sigma;\\sb{\\rm d}</span>+ was temperature and energy dependent, but was still much higher than <span class=\"etd-inline-math\">&sigma;\\sb{\\rm d,th}.</span> Abrupt tailored depth profiles were easily obtained by controlling the ion current; layers <span class=\"etd-inline-math\">&delta;</span>-doped with a 250 V Sb-ion beam were $\\le$2 nm wide.","abstract_has_math":true,"creators":["Markert, Lucia Chen"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Engineering","degree_department":null,"school":null,"contributors":["Greene, Joseph E."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:00:54Z","date_published":"2011-05-07T13:00:54Z","updated_at":"2026-07-22T22:25:17Z","subjects":["Physics, Condensed Matter","Engineering, Materials Science"],"languages":["eng"],"rights":["Copyright 1992 Markert, Lucia Chen"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9236532","(UMI)AAI9236532"],"render_values":[{"text":"AAI9236532","href":null,"code":true},{"text":"(UMI)AAI9236532","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21184","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Greene, Joseph E."]},{"key":"dc:creator","label":"Author","values":["Markert, Lucia Chen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:00:54Z","10000-01-01","1992"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Engineering"]},{"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":["Physics, Condensed Matter","Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1992 Markert, Lucia Chen"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9236532","(UMI)AAI9236532","http://hdl.handle.net/2142/21184"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thermal and accelerated-ion doping, with In and Sb, during Si(001) molecular-beam epitaxy were investigated as a function of growth temperature T$\\sb{\\rm s}$ (500-1050$\\sp\\circ$C), dopant energy E$\\sb{\\rm d}$ (thermal-500 eV), and Si deposition rate R$\\sb{\\rm Si}$ (0.18-4.7 $\\mu$m h$\\sp{-1}).$ Surface segregation during thermal doping led to severe profile broadening and low temperature-dependent incorporation probabilities $\\sigma\\sb{\\rm d,th}.$ On the other hand, $\\sigma\\sb{\\rm d}$+ for In-ions at energies E$\\sb{\\rm In}$+ $\\ge$ 200 eV or Sb-ions accelerated by potentials V$\\sb{\\rm Sb}$+ $\\ge$ 300 V was essentially unity up to T$\\sb{\\rm s}\\sim850$-900$\\sp\\circ$C. At lower ion energies, $\\sigma\\sb{\\rm d}$+ was temperature and energy dependent, but was still much higher than $\\sigma\\sb{\\rm d,th}.$ Abrupt tailored depth profiles were easily obtained by controlling the ion current; layers $\\delta$-doped with a 250 V Sb-ion beam were $\\le$2 nm wide.","Concentration transient analysis (CTA) was developed in order to obtain segregation data from SIMS depth profiles of modulation-doped films. The surface-segregated layer, trapped in the film using programmed T$\\sb{\\rm s}$ changes, formed a concentration spike with an integrated area corresponding to the dopant surface coverage $\\theta\\sb{\\rm d}.$ CTA measurements showed that Sb coevaporation led to $\\theta\\sb{\\rm Sb}$ values as high as 0.9 ML at 675$\\sp\\circ$C, whereas segregation was insignificant, $\\theta\\sb{\\rm Sb}\\le4\\times10\\sp{-3}$ ML, in films doped with Sb-ions accelerated by 100 V. Effective Sb segregation energies $\\rm \\Delta G\\sb{Sb},$ calculated using CTA data, were both T$\\sb{\\rm s}$ and R$\\sb{\\rm Si}$ dependent. Since the segregant supply in these experiments was at the surface, rather than in the bulk, the effective $\\rm \\Delta G\\sb{Sb}$ values were related to segregation from near-surface sites which reach equilibrium with the surface during film growth.","The $\\delta$-doping and surface segregation results were the basis for modifying the dopant incorporation model developed by our group. By accounting for film growth separately from the equations describing dopant populations in the lattice potential wells, diffusion becomes the only mechanism for changing concentration gradients. A minimum of four sites between the surface and the bulk were necessary to describe the temperature and growth-rate dependences of Sb incorporation and segregation. The energy parameters for the intermediate sites were obtained by fitting experimental Sb incorporation and segregation data.","Made available in DSpace on 2011-05-07T13:00:54Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9236532.pdf: 3787963 bytes, checksum: 7648e2c71bac014600f5eb4c4908c979 (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:49:03Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:22:16-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Thermal and low-energy ion doping of silicon(001) during molecular beam epitaxy: Dopant incorporation kinetics and mechanisms"]}]}],"canonical_facts":{"dc:contributor":["Greene, Joseph E."],"dc:creator":["Markert, Lucia Chen"],"dc:date":["2011-05-07T13:00:54Z","10000-01-01","1992"],"dc:description":["Thermal and accelerated-ion doping, with In and Sb, during Si(001) molecular-beam epitaxy were investigated as a function of growth temperature T$\\sb{\\rm s}$ (500-1050$\\sp\\circ$C), dopant energy E$\\sb{\\rm d}$ (thermal-500 eV), and Si deposition rate R$\\sb{\\rm Si}$ (0.18-4.7 $\\mu$m h$\\sp{-1}).$ Surface segregation during thermal doping led to severe profile broadening and low temperature-dependent incorporation probabilities $\\sigma\\sb{\\rm d,th}.$ On the other hand, $\\sigma\\sb{\\rm d}$+ for In-ions at energies E$\\sb{\\rm In}$+ $\\ge$ 200 eV or Sb-ions accelerated by potentials V$\\sb{\\rm Sb}$+ $\\ge$ 300 V was essentially unity up to T$\\sb{\\rm s}\\sim850$-900$\\sp\\circ$C. At lower ion energies, $\\sigma\\sb{\\rm d}$+ was temperature and energy dependent, but was still much higher than $\\sigma\\sb{\\rm d,th}.$ Abrupt tailored depth profiles were easily obtained by controlling the ion current; layers $\\delta$-doped with a 250 V Sb-ion beam were $\\le$2 nm wide.","Concentration transient analysis (CTA) was developed in order to obtain segregation data from SIMS depth profiles of modulation-doped films. The surface-segregated layer, trapped in the film using programmed T$\\sb{\\rm s}$ changes, formed a concentration spike with an integrated area corresponding to the dopant surface coverage $\\theta\\sb{\\rm d}.$ CTA measurements showed that Sb coevaporation led to $\\theta\\sb{\\rm Sb}$ values as high as 0.9 ML at 675$\\sp\\circ$C, whereas segregation was insignificant, $\\theta\\sb{\\rm Sb}\\le4\\times10\\sp{-3}$ ML, in films doped with Sb-ions accelerated by 100 V. Effective Sb segregation energies $\\rm \\Delta G\\sb{Sb},$ calculated using CTA data, were both T$\\sb{\\rm s}$ and R$\\sb{\\rm Si}$ dependent. Since the segregant supply in these experiments was at the surface, rather than in the bulk, the effective $\\rm \\Delta G\\sb{Sb}$ values were related to segregation from near-surface sites which reach equilibrium with the surface during film growth.","The $\\delta$-doping and surface segregation results were the basis for modifying the dopant incorporation model developed by our group. By accounting for film growth separately from the equations describing dopant populations in the lattice potential wells, diffusion becomes the only mechanism for changing concentration gradients. A minimum of four sites between the surface and the bulk were necessary to describe the temperature and growth-rate dependences of Sb incorporation and segregation. The energy parameters for the intermediate sites were obtained by fitting experimental Sb incorporation and segregation data.","Made available in DSpace on 2011-05-07T13:00:54Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9236532.pdf: 3787963 bytes, checksum: 7648e2c71bac014600f5eb4c4908c979 (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:49:03Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:22:16-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9236532","(UMI)AAI9236532","http://hdl.handle.net/2142/21184"],"dc:language":["eng"],"dc:rights":["Copyright 1992 Markert, Lucia Chen"],"dc:subject":["Physics, Condensed Matter","Engineering, Materials Science"],"dc:title":["Thermal and low-energy ion doping of silicon(001) during molecular beam epitaxy: Dopant incorporation kinetics and mechanisms"],"dc:type":["text"],"thesis:degree_discipline":["Materials Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:17Z"}