{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/25808"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/25808","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Investigations of electron scattering mechanisms at the silicon-silicon dioxide interface","abstract":"\"A detailed theoretical and experimental investigation was conducted to determine the possible scattering mechanisms of electrons at the silicon-silicon dioxide interface. Theoretical surface conductivity mobility in a semiconductor space-charge region for the temperature range 1000K to 4000K was calculated using a classical Boltzmann-Fuchs equation with constant field and constant relaxation time approximations. The surface scattering mechanisms were included in the Fuchs boundary condition for normally incident scattering. The mechanisms investigated are diffuse scattering, constant partially specular scattering, de Broglie wave scattering, and shielded Coulomb surface state scattering. The momentum relaxation time characteristic of the channel region was calculated by including the screening of the impurity ions by the electrons in the inversion region. Experimental surface conductivity mobility measurements using n-channel metal-oxide-semiconductor (MOS) transistors for a wide change in impurity concentration are compared with the theoretical curves. These transistors were fabricated with the lowest possible number of surface states. For thermally oxidized silicon surfaces with minimum surface states, diffuse scattering and constant \"\"p\"\" scattering do not explain the experimental results. The conclusion is that the surface scattering is not completely diffuse. At least two additional mechanisms must be considered for surface scattering mechanisms? de Broglie wave scattering and shielded Coulomb surface state scatteringo De Broglie wave scattering is particularly important for temperatures above 2000K and is the best one parameter model for surface scattering over the 1000K to 4000K temperature range. The surface roughness based on the above model is 3 to 6 ~ or a few lattice spacings, indicating that thermally oxidized silicon has a microscopically smooth surface. Surface state scattering still appears to exist even for minimum surface state conditions and is particularly effective for temperatures below 200 oK. The anisotropy in the surface conductivity, predicted classically by Ham and Mattis and quantum mechanically by Stern and Howard for the (110) surface of silicon, has been observed.. The quantum mechanical treatment has been extended to finite temperatures for comparison with experiment. The conclusion is that the effective mass approximation near the surface is plausible from both the anisotropy measurements and from the small values of the surface roughness. It is also concluded that a quantum mechanical treatment is necessary for low temperatures.\"","abstract_html":""A detailed theoretical and experimental investigation was conducted to determine the possible scattering mechanisms of electrons at the silicon-silicon dioxide interface. Theoretical surface conductivity mobility in a semiconductor space-charge region for the temperature range 1000K to 4000K was calculated using a classical Boltzmann-Fuchs equation with constant field and constant relaxation time approximations. The surface scattering mechanisms were included in the Fuchs boundary condition for normally incident scattering. The mechanisms investigated are diffuse scattering, constant partially specular scattering, de Broglie wave scattering, and shielded Coulomb surface state scattering. The momentum relaxation time characteristic of the channel region was calculated by including the screening of the impurity ions by the electrons in the inversion region. Experimental surface conductivity mobility measurements using n-channel metal-oxide-semiconductor (MOS) transistors for a wide change in impurity concentration are compared with the theoretical curves. These transistors were fabricated with the lowest possible number of surface states. For thermally oxidized silicon surfaces with minimum surface states, diffuse scattering and constant ""p"" scattering do not explain the experimental results. The conclusion is that the surface scattering is not completely diffuse. At least two additional mechanisms must be considered for surface scattering mechanisms? de Broglie wave scattering and shielded Coulomb surface state scatteringo De Broglie wave scattering is particularly important for temperatures above 2000K and is the best one parameter model for surface scattering over the 1000K to 4000K temperature range. The surface roughness based on the above model is 3 to 6 ~ or a few lattice spacings, indicating that thermally oxidized silicon has a microscopically smooth surface. Surface state scattering still appears to exist even for minimum surface state conditions and is particularly effective for temperatures below 200 oK. The anisotropy in the surface conductivity, predicted classically by Ham and Mattis and quantum mechanically by Stern and Howard for the (110) surface of silicon, has been observed.. The quantum mechanical treatment has been extended to finite temperatures for comparison with experiment. The conclusion is that the effective mass approximation near the surface is plausible from both the anisotropy measurements and from the small values of the surface roughness. It is also concluded that a quantum mechanical treatment is necessary for low temperatures."","abstract_has_math":false,"creators":["Edwards, John Richard"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Sah, C.T."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-07-14T14:47:07Z","date_published":"2011-07-14T14:47:07Z","updated_at":"2026-07-22T22:25:26Z","subjects":["electron scattering mechanisms","silicon-silicon dioxide interface","surface conductivity mobility","semiconductor space-charge region"],"languages":["en"],"rights":["1970 John Richard Edwards"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["6065186"],"render_values":[{"text":"6065186","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/25808","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Sah, C.T."]},{"key":"dc:creator","label":"Author","values":["Edwards, John Richard"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-07-14T14:47:07Z","10000-01-01","1970"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["electron scattering mechanisms","silicon-silicon dioxide interface","surface conductivity mobility","semiconductor space-charge region"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1970 John Richard Edwards"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["6065186","http://hdl.handle.net/2142/25808"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"A detailed theoretical and experimental investigation was conducted to determine the possible scattering mechanisms of electrons at the silicon-silicon dioxide interface. Theoretical surface conductivity mobility in a semiconductor space-charge region for the temperature range 1000K to 4000K was calculated using a classical Boltzmann-Fuchs equation with constant field and constant relaxation time approximations. The surface scattering mechanisms were included in the Fuchs boundary condition for normally incident scattering. The mechanisms investigated are diffuse scattering, constant partially specular scattering, de Broglie wave scattering, and shielded Coulomb surface state scattering. The momentum relaxation time characteristic of the channel region was calculated by including the screening of the impurity ions by the electrons in the inversion region. Experimental surface conductivity mobility measurements using n-channel metal-oxide-semiconductor (MOS) transistors for a wide change in impurity concentration are compared with the theoretical curves. These transistors were fabricated with the lowest possible number of surface states. For thermally oxidized silicon surfaces with minimum surface states, diffuse scattering and constant \"\"p\"\" scattering do not explain the experimental results. The conclusion is that the surface scattering is not completely diffuse. At least two additional mechanisms must be considered for surface scattering mechanisms? de Broglie wave scattering and shielded Coulomb surface state scatteringo De Broglie wave scattering is particularly important for temperatures above 2000K and is the best one parameter model for surface scattering over the 1000K to 4000K temperature range. The surface roughness based on the above model is 3 to 6 ~ or a few lattice spacings, indicating that thermally oxidized silicon has a microscopically smooth surface. Surface state scattering still appears to exist even for minimum surface state conditions and is particularly effective for temperatures below 200 oK. The anisotropy in the surface conductivity, predicted classically by Ham and Mattis and quantum mechanically by Stern and Howard for the (110) surface of silicon, has been observed.. The quantum mechanical treatment has been extended to finite temperatures for comparison with experiment. The conclusion is that the effective mass approximation near the surface is plausible from both the anisotropy measurements and from the small values of the surface roughness. It is also concluded that a quantum mechanical treatment is necessary for low temperatures.\"","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:47:07Z No. of bitstreams: 1 1970_edwardsj.pdf: 4668253 bytes, checksum: de27220af11e99969f024a1ae0eacb33 (MD5)","Made available in DSpace on 2011-07-14T14:47:07Z (GMT). No. of bitstreams: 1 1970_edwardsj.pdf: 4668253 bytes, checksum: de27220af11e99969f024a1ae0eacb33 (MD5) Previous issue date: 1970","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:47:07Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:33:20-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["Investigations of electron scattering mechanisms at the silicon-silicon dioxide interface"]}]}],"canonical_facts":{"dc:contributor":["Sah, C.T."],"dc:creator":["Edwards, John Richard"],"dc:date":["2011-07-14T14:47:07Z","10000-01-01","1970"],"dc:description":["\"A detailed theoretical and experimental investigation was conducted to determine the possible scattering mechanisms of electrons at the silicon-silicon dioxide interface. Theoretical surface conductivity mobility in a semiconductor space-charge region for the temperature range 1000K to 4000K was calculated using a classical Boltzmann-Fuchs equation with constant field and constant relaxation time approximations. The surface scattering mechanisms were included in the Fuchs boundary condition for normally incident scattering. The mechanisms investigated are diffuse scattering, constant partially specular scattering, de Broglie wave scattering, and shielded Coulomb surface state scattering. The momentum relaxation time characteristic of the channel region was calculated by including the screening of the impurity ions by the electrons in the inversion region. Experimental surface conductivity mobility measurements using n-channel metal-oxide-semiconductor (MOS) transistors for a wide change in impurity concentration are compared with the theoretical curves. These transistors were fabricated with the lowest possible number of surface states. For thermally oxidized silicon surfaces with minimum surface states, diffuse scattering and constant \"\"p\"\" scattering do not explain the experimental results. The conclusion is that the surface scattering is not completely diffuse. At least two additional mechanisms must be considered for surface scattering mechanisms? de Broglie wave scattering and shielded Coulomb surface state scatteringo De Broglie wave scattering is particularly important for temperatures above 2000K and is the best one parameter model for surface scattering over the 1000K to 4000K temperature range. The surface roughness based on the above model is 3 to 6 ~ or a few lattice spacings, indicating that thermally oxidized silicon has a microscopically smooth surface. Surface state scattering still appears to exist even for minimum surface state conditions and is particularly effective for temperatures below 200 oK. The anisotropy in the surface conductivity, predicted classically by Ham and Mattis and quantum mechanically by Stern and Howard for the (110) surface of silicon, has been observed.. The quantum mechanical treatment has been extended to finite temperatures for comparison with experiment. The conclusion is that the effective mass approximation near the surface is plausible from both the anisotropy measurements and from the small values of the surface roughness. It is also concluded that a quantum mechanical treatment is necessary for low temperatures.\"","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:47:07Z No. of bitstreams: 1 1970_edwardsj.pdf: 4668253 bytes, checksum: de27220af11e99969f024a1ae0eacb33 (MD5)","Made available in DSpace on 2011-07-14T14:47:07Z (GMT). No. of bitstreams: 1 1970_edwardsj.pdf: 4668253 bytes, checksum: de27220af11e99969f024a1ae0eacb33 (MD5) Previous issue date: 1970","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-14T14:47:07Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:33:20-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["6065186","http://hdl.handle.net/2142/25808"],"dc:language":["en"],"dc:rights":["1970 John Richard Edwards"],"dc:subject":["electron scattering mechanisms","silicon-silicon dioxide interface","surface conductivity mobility","semiconductor space-charge region"],"dc:title":["Investigations of electron scattering mechanisms at the silicon-silicon dioxide interface"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:26Z"}