{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:59384"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:59384","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Fundamental processes in growth of reactive DC magnetron sputtered thin films","abstract":"This work seeks an atomistic understanding of fundamental processes in DC reactive magnetron sputtering of optical functional coatings. From a comparative study for different metal-oxygen combinations, which is illustrated by two oxide deposition reports on neighbouring elements - hafnium and tantalum, a surprising structural trend is revealed. While films are obtained crystalline at room temperature for group IV oxides, amorphous films were obtained for groups V and VI oxides. This observation can not be explained by the known growth laws including the Thornton model. The trend is attributed to the impact of energetic particles, originating from the oxidized target, which bombard the growing film. This scenario is supported by the measured target characteristics and evolution of deposition stress of the films and related to the variation in the activation energy for negative oxygen ion formation. Besides comparing the findings with other reports, possible chemical effects on structure are also ruled out. Observed backsputtering for the amorphous films provides further evidence for a model based on energetic particle bombardment. To improve on the low growth rates and high film surface roughness characterizing sputtered oxides, the approach of adding nitrogen to the sputter atmosphere leads to films with superior properties and growth conditions. An understanding to the cause of these beneficial effects was sought by examining the film composition and crystallographic structure for grown zirconium oxynitrides. Based on a thermochemical description together with a modeling of formation kinetics a film formation mechanism is proposed, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N2 flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure.","abstract_html":"This work seeks an atomistic understanding of fundamental processes in DC reactive magnetron sputtering of optical functional coatings. From a comparative study for different metal-oxygen combinations, which is illustrated by two oxide deposition reports on neighbouring elements - hafnium and tantalum, a surprising structural trend is revealed. While films are obtained crystalline at room temperature for group IV oxides, amorphous films were obtained for groups V and VI oxides. This observation can not be explained by the known growth laws including the Thornton model. The trend is attributed to the impact of energetic particles, originating from the oxidized target, which bombard the growing film. This scenario is supported by the measured target characteristics and evolution of deposition stress of the films and related to the variation in the activation energy for negative oxygen ion formation. Besides comparing the findings with other reports, possible chemical effects on structure are also ruled out. Observed backsputtering for the amorphous films provides further evidence for a model based on energetic particle bombardment. To improve on the low growth rates and high film surface roughness characterizing sputtered oxides, the approach of adding nitrogen to the sputter atmosphere leads to films with superior properties and growth conditions. An understanding to the cause of these beneficial effects was sought by examining the film composition and crystallographic structure for grown zirconium oxynitrides. Based on a thermochemical description together with a modeling of formation kinetics a film formation mechanism is proposed, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N2 flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure.","abstract_has_math":false,"creators":["Ngaruiya, James Mbiyu"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Wuttig, Matthias"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004","date_published":"2004","updated_at":"2026-07-30T19:42:39Z","subjects":["info:eu-repo/classification/ddc/530","Optische Schicht","Übergangsmetalloxide","Schichtwachstum","Magnetronsputtern","Physik","reactive sputtering","structure","film growth"],"languages":["eng"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121173%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121173%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121173%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/59384","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wuttig, Matthias"]},{"key":"dc:creator","label":"Author","values":["Ngaruiya, James Mbiyu"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2004"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/doi/10.18154/RWTH-CONV-121173","info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-7906"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/530","Optische Schicht","Übergangsmetalloxide","Schichtwachstum","Magnetronsputtern","Physik","reactive sputtering","structure","film growth"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/59384","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121173%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This work seeks an atomistic understanding of fundamental processes in DC reactive magnetron sputtering of optical functional coatings. From a comparative study for different metal-oxygen combinations, which is illustrated by two oxide deposition reports on neighbouring elements - hafnium and tantalum, a surprising structural trend is revealed. While films are obtained crystalline at room temperature for group IV oxides, amorphous films were obtained for groups V and VI oxides. This observation can not be explained by the known growth laws including the Thornton model. The trend is attributed to the impact of energetic particles, originating from the oxidized target, which bombard the growing film. This scenario is supported by the measured target characteristics and evolution of deposition stress of the films and related to the variation in the activation energy for negative oxygen ion formation. Besides comparing the findings with other reports, possible chemical effects on structure are also ruled out. Observed backsputtering for the amorphous films provides further evidence for a model based on energetic particle bombardment. To improve on the low growth rates and high film surface roughness characterizing sputtered oxides, the approach of adding nitrogen to the sputter atmosphere leads to films with superior properties and growth conditions. An understanding to the cause of these beneficial effects was sought by examining the film composition and crystallographic structure for grown zirconium oxynitrides. Based on a thermochemical description together with a modeling of formation kinetics a film formation mechanism is proposed, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N2 flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University V, 150 S. : Ill., graph. Darst. (2004). doi:10.18154/RWTH-CONV-121173 = Aachen, Techn. Hochsch., Diss., 2004"]},{"key":"dc:title","label":"Title","values":["Fundamental processes in growth of reactive DC magnetron sputtered thin films"]}]}],"canonical_facts":{"dc:contributor":["Wuttig, Matthias"],"dc:coverage":["DE"],"dc:creator":["Ngaruiya, James Mbiyu"],"dc:date":["2004"],"dc:description":["This work seeks an atomistic understanding of fundamental processes in DC reactive magnetron sputtering of optical functional coatings. From a comparative study for different metal-oxygen combinations, which is illustrated by two oxide deposition reports on neighbouring elements - hafnium and tantalum, a surprising structural trend is revealed. While films are obtained crystalline at room temperature for group IV oxides, amorphous films were obtained for groups V and VI oxides. This observation can not be explained by the known growth laws including the Thornton model. The trend is attributed to the impact of energetic particles, originating from the oxidized target, which bombard the growing film. This scenario is supported by the measured target characteristics and evolution of deposition stress of the films and related to the variation in the activation energy for negative oxygen ion formation. Besides comparing the findings with other reports, possible chemical effects on structure are also ruled out. Observed backsputtering for the amorphous films provides further evidence for a model based on energetic particle bombardment. To improve on the low growth rates and high film surface roughness characterizing sputtered oxides, the approach of adding nitrogen to the sputter atmosphere leads to films with superior properties and growth conditions. An understanding to the cause of these beneficial effects was sought by examining the film composition and crystallographic structure for grown zirconium oxynitrides. Based on a thermochemical description together with a modeling of formation kinetics a film formation mechanism is proposed, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N2 flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure."],"dc:identifier":["https://publications.rwth-aachen.de/record/59384","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121173%22"],"dc:language":["eng"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/doi/10.18154/RWTH-CONV-121173","info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-7906"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University V, 150 S. : Ill., graph. Darst. (2004). doi:10.18154/RWTH-CONV-121173 = Aachen, Techn. Hochsch., Diss., 2004"],"dc:subject":["info:eu-repo/classification/ddc/530","Optische Schicht","Übergangsmetalloxide","Schichtwachstum","Magnetronsputtern","Physik","reactive sputtering","structure","film growth"],"dc:title":["Fundamental processes in growth of reactive DC magnetron sputtered thin films"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:42:39Z"}