{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/83949"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/83949","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Bulk Growth of Semiconductor Crystals in a Magnetic Field: A Study of Dopant Transport","abstract":"Our model for the unsteady transport of a dopant during the entire period of time required to grow a crystal assumes that the externally applied magnetic field is sufficiently strong that inertial effects and convective heat transfer are negligible. We divide the semiconductor melt into (1) mass-diffusion boundary layers where convective and diffusive mass transfer are comparable, and (2) a core region where diffusion is negligible, so that the concentration of each fluid particle is constant. A Lagrangian description of motion is used to track each fluid particle during its transits across the core between diffusion layers. The dopant distribution in each layer depends on the concentrations of all fluid particles which are entering this layer. The dopant distribution is very non-uniform throughout the melt and is far from the instantaneous steady state at each stage during crystal growth. Our transient model is the first model to predict the dopant distribution in the entire crystal. The predictions of this asymptotic model are confirmed by a numerical solution to the full mass transport equation.","abstract_html":"Our model for the unsteady transport of a dopant during the entire period of time required to grow a crystal assumes that the externally applied magnetic field is sufficiently strong that inertial effects and convective heat transfer are negligible. We divide the semiconductor melt into (1) mass-diffusion boundary layers where convective and diffusive mass transfer are comparable, and (2) a core region where diffusion is negligible, so that the concentration of each fluid particle is constant. A Lagrangian description of motion is used to track each fluid particle during its transits across the core between diffusion layers. The dopant distribution in each layer depends on the concentrations of all fluid particles which are entering this layer. The dopant distribution is very non-uniform throughout the melt and is far from the instantaneous steady state at each stage during crystal growth. Our transient model is the first model to predict the dopant distribution in the entire crystal. The predictions of this asymptotic model are confirmed by a numerical solution to the full mass transport equation.","abstract_has_math":false,"creators":["Ma, Nancy"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Walker, J.S."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T21:12:50Z","date_published":"2015-09-25T21:12:50Z","updated_at":"2026-07-22T22:26:22Z","subjects":["Engineering, Materials Science"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9717303"],"render_values":[{"text":"(MiAaPQ)AAI9717303","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/83949","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Walker, J.S."]},{"key":"dc:creator","label":"Author","values":["Ma, Nancy"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T21:12:50Z","10000-01-01","1997"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical 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":["Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/83949","(MiAaPQ)AAI9717303"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Our model for the unsteady transport of a dopant during the entire period of time required to grow a crystal assumes that the externally applied magnetic field is sufficiently strong that inertial effects and convective heat transfer are negligible. We divide the semiconductor melt into (1) mass-diffusion boundary layers where convective and diffusive mass transfer are comparable, and (2) a core region where diffusion is negligible, so that the concentration of each fluid particle is constant. A Lagrangian description of motion is used to track each fluid particle during its transits across the core between diffusion layers. The dopant distribution in each layer depends on the concentrations of all fluid particles which are entering this layer. The dopant distribution is very non-uniform throughout the melt and is far from the instantaneous steady state at each stage during crystal growth. Our transient model is the first model to predict the dopant distribution in the entire crystal. The predictions of this asymptotic model are confirmed by a numerical solution to the full mass transport equation.","Made available in DSpace on 2015-09-25T21:12:50Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9717303.pdf: 6033791 bytes, checksum: 766fb47629c05573da2d5b971bb78486 (MD5) Previous issue date: 1997","Embargo set by: Seth Robbins for item 85230 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","157 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997."]},{"key":"dc:title","label":"Title","values":["Bulk Growth of Semiconductor Crystals in a Magnetic Field: A Study of Dopant Transport"]}]}],"canonical_facts":{"dc:contributor":["Walker, J.S."],"dc:creator":["Ma, Nancy"],"dc:date":["2015-09-25T21:12:50Z","10000-01-01","1997"],"dc:description":["Our model for the unsteady transport of a dopant during the entire period of time required to grow a crystal assumes that the externally applied magnetic field is sufficiently strong that inertial effects and convective heat transfer are negligible. We divide the semiconductor melt into (1) mass-diffusion boundary layers where convective and diffusive mass transfer are comparable, and (2) a core region where diffusion is negligible, so that the concentration of each fluid particle is constant. A Lagrangian description of motion is used to track each fluid particle during its transits across the core between diffusion layers. The dopant distribution in each layer depends on the concentrations of all fluid particles which are entering this layer. The dopant distribution is very non-uniform throughout the melt and is far from the instantaneous steady state at each stage during crystal growth. Our transient model is the first model to predict the dopant distribution in the entire crystal. The predictions of this asymptotic model are confirmed by a numerical solution to the full mass transport equation.","Made available in DSpace on 2015-09-25T21:12:50Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9717303.pdf: 6033791 bytes, checksum: 766fb47629c05573da2d5b971bb78486 (MD5) Previous issue date: 1997","Embargo set by: Seth Robbins for item 85230 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","157 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997."],"dc:identifier":["http://hdl.handle.net/2142/83949","(MiAaPQ)AAI9717303"],"dc:language":["eng"],"dc:subject":["Engineering, Materials Science"],"dc:title":["Bulk Growth of Semiconductor Crystals in a Magnetic Field: A Study of Dopant Transport"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:22Z"}