{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/8452"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/8452","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Characterization of OMVPE-grown GaSb-based epilayers using in situ reflectance and ex situ TEM","abstract":"The focus of this thesis was to investigate and characterize GaSb, GaInAsSb, and AlGaAsSb epilayers grown by organometallic vapor phase epitaxy (OMVPE). These epilayers were principally characterized using in situ spectral reflectance and ex situ transmission electron microscopy (TEM). An in situ spectral (380-1100 nm) reflectance monitoring system was designed and fitted to the OMVPE reactor. It was determined that longer wavelengths are more useful for quantitative growth rate analysis, while shorter wavelengths are more sensitive to the GaSb substrate oxide desorption process. It was also determined that the GaInAsSb and AlGaAsSb alloy compositions could be determined accurately using in situ reflectance ratios. Use of the in situ reflectance monitor to efficiently perform necessary reactor/growth calibrations was also demonstrated. Analytic functions were used to model the refractive indices of GaSb, AlGaAsSb, and GaInAsSb. Specifically, Adachi's Model Dielectric Function [1, 2] was curve-fit to data for GaSb between 400 and 1000 nm, and fourth-order polynomials were fit to data for GaSb and GaInAsSb between 1 and 3 gnm. A linear interpolation of binary functions was used to generate a refractive index model for AlGaAsSb between 1 and 3 m as a function of Al fraction. These models were helpful in interpreting in situ reflectance data, and also in designing distributed Bragg reflectors. Phase separation in GaInAsSb was studied using TEM. A wide range of microstructures was observed, from nearly homogeneous to strongly phase separated.","abstract_html":"The focus of this thesis was to investigate and characterize GaSb, GaInAsSb, and AlGaAsSb epilayers grown by organometallic vapor phase epitaxy (OMVPE). These epilayers were principally characterized using in situ spectral reflectance and ex situ transmission electron microscopy (TEM). An in situ spectral (380-1100 nm) reflectance monitoring system was designed and fitted to the OMVPE reactor. It was determined that longer wavelengths are more useful for quantitative growth rate analysis, while shorter wavelengths are more sensitive to the GaSb substrate oxide desorption process. It was also determined that the GaInAsSb and AlGaAsSb alloy compositions could be determined accurately using in situ reflectance ratios. Use of the in situ reflectance monitor to efficiently perform necessary reactor/growth calibrations was also demonstrated. Analytic functions were used to model the refractive indices of GaSb, AlGaAsSb, and GaInAsSb. Specifically, Adachi's Model Dielectric Function [1, 2] was curve-fit to data for GaSb between 400 and 1000 nm, and fourth-order polynomials were fit to data for GaSb and GaInAsSb between 1 and 3 gnm. A linear interpolation of binary functions was used to generate a refractive index model for AlGaAsSb between 1 and 3 m as a function of Al fraction. These models were helpful in interpreting in situ reflectance data, and also in designing distributed Bragg reflectors. Phase separation in GaInAsSb was studied using TEM. A wide range of microstructures was observed, from nearly homogeneous to strongly phase separated.","abstract_has_math":false,"creators":["Vineis, Christopher J. (Christopher Joseph), 1974-"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.","school":null,"contributors":[],"advisors":["Christine A. Wang and Klavs F. Jensen."],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001","date_published":"2001","updated_at":"2026-07-22T22:21:17Z","subjects":["Materials Science and Engineering."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/8452","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Christine A. Wang and Klavs F. 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They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/8452"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001.","Includes bibliographical references (leaves 227-238)."]},{"key":"dc:description.abstract","label":"Abstract","values":["The focus of this thesis was to investigate and characterize GaSb, GaInAsSb, and AlGaAsSb epilayers grown by organometallic vapor phase epitaxy (OMVPE). These epilayers were principally characterized using in situ spectral reflectance and ex situ transmission electron microscopy (TEM). An in situ spectral (380-1100 nm) reflectance monitoring system was designed and fitted to the OMVPE reactor. It was determined that longer wavelengths are more useful for quantitative growth rate analysis, while shorter wavelengths are more sensitive to the GaSb substrate oxide desorption process. It was also determined that the GaInAsSb and AlGaAsSb alloy compositions could be determined accurately using in situ reflectance ratios. Use of the in situ reflectance monitor to efficiently perform necessary reactor/growth calibrations was also demonstrated. Analytic functions were used to model the refractive indices of GaSb, AlGaAsSb, and GaInAsSb. Specifically, Adachi's Model Dielectric Function [1, 2] was curve-fit to data for GaSb between 400 and 1000 nm, and fourth-order polynomials were fit to data for GaSb and GaInAsSb between 1 and 3 gnm. A linear interpolation of binary functions was used to generate a refractive index model for AlGaAsSb between 1 and 3 m as a function of Al fraction. These models were helpful in interpreting in situ reflectance data, and also in designing distributed Bragg reflectors. Phase separation in GaInAsSb was studied using TEM. A wide range of microstructures was observed, from nearly homogeneous to strongly phase separated.","(cont.) It was seen that in phase separated samples, the composition modulations typically created and coupled to morphological perturbations in the surface. One interesting manifestation of the phase separation was the spontaneous formation of a natural superlattice (period typically 10-30 nm) throughout the epilayer. This superlattice had two variants: one parallel to the growth surface, and one tilted with respect to the growth surface. It was discovered that the tilted superlattice was coupled to surface to relieve surface strain associated with the superlattice ..."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Characterization of OMVPE-grown GaSb-based epilayers using in situ reflectance and ex situ TEM"]}]}],"canonical_facts":{"dc:contributor.advisor":["Christine A. Wang and Klavs F. Jensen."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Materials Science and Engineering."],"dc:creator":["Vineis, Christopher J. (Christopher Joseph), 1974-"],"dc:date.accessioned":["2005-08-23T20:17:45Z"],"dc:date.available":["2005-08-23T20:17:45Z"],"dc:date.issued":["2001"],"dc:description":["Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001.","Includes bibliographical references (leaves 227-238)."],"dc:description.abstract":["The focus of this thesis was to investigate and characterize GaSb, GaInAsSb, and AlGaAsSb epilayers grown by organometallic vapor phase epitaxy (OMVPE). These epilayers were principally characterized using in situ spectral reflectance and ex situ transmission electron microscopy (TEM). An in situ spectral (380-1100 nm) reflectance monitoring system was designed and fitted to the OMVPE reactor. It was determined that longer wavelengths are more useful for quantitative growth rate analysis, while shorter wavelengths are more sensitive to the GaSb substrate oxide desorption process. It was also determined that the GaInAsSb and AlGaAsSb alloy compositions could be determined accurately using in situ reflectance ratios. Use of the in situ reflectance monitor to efficiently perform necessary reactor/growth calibrations was also demonstrated. Analytic functions were used to model the refractive indices of GaSb, AlGaAsSb, and GaInAsSb. Specifically, Adachi's Model Dielectric Function [1, 2] was curve-fit to data for GaSb between 400 and 1000 nm, and fourth-order polynomials were fit to data for GaSb and GaInAsSb between 1 and 3 gnm. A linear interpolation of binary functions was used to generate a refractive index model for AlGaAsSb between 1 and 3 m as a function of Al fraction. These models were helpful in interpreting in situ reflectance data, and also in designing distributed Bragg reflectors. Phase separation in GaInAsSb was studied using TEM. A wide range of microstructures was observed, from nearly homogeneous to strongly phase separated.","(cont.) It was seen that in phase separated samples, the composition modulations typically created and coupled to morphological perturbations in the surface. One interesting manifestation of the phase separation was the spontaneous formation of a natural superlattice (period typically 10-30 nm) throughout the epilayer. This superlattice had two variants: one parallel to the growth surface, and one tilted with respect to the growth surface. It was discovered that the tilted superlattice was coupled to surface to relieve surface strain associated with the superlattice ..."],"dc:description.degree":["Ph.D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/8452"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Materials Science and Engineering."],"dc:title":["Characterization of OMVPE-grown GaSb-based epilayers using in situ reflectance and ex situ TEM"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:17Z"}