{"id":{"repo_id":"colo-mines","oai_identifier":"oai:repository.mines.edu:11124/172268"},"canonical_url":"https://search.dev.ndltd.org/etd/colo-mines/oai:repository.mines.edu:11124/172268","repository":{"repo_id":"colo-mines","name":"Colorado School of Mines","base_url":"https://repository.mines.edu/server/oai/request"},"display":{"title":"Surface reaction mechanisms during the atomic layer deposition of silicon-based dielectrics","abstract":"The continuous shrinking of semiconductor devices beyond the current 14 nm technology node has kindled a need for the low-temperature (≤400 °C) highly-conformal (>95%) atomic layer deposition (ALD) of Si-based dielectric films for applications such as sidewall spacers in multiple patterning. In this work, we have primarily focused on understanding the surface reaction mechanisms during the ALD of Si-based dielectric films using in situ attenuated total reflection Fourier transform infrared spectroscopy. Initially, we looked at a baseline SiNx ALD process using alternating exposures of Si2Cl6 and NH3 plasma. Our infrared spectra show that H was incorporated during both half cycles in the form of –NH species, leading to a high H content and poor film quality. To improve the film quality, two approaches were considered: C incorporation and H content reduction. For the first approach, we developed and tested a framework for the incorporation of C during SiNx and SiO2 ALD to deposit SiCxNy and SiCxOy films. The framework was used to develop a novel SiCxNy ALD process using Si2Cl6 and CH3NH2 plasma. This process incorporated up to ~10% C in the form of Si–N=C=N–Si species, but H was once again incorporated during both half-cycles leading to a similar H content and film quality as the baseline SiNx ALD process. For the second approach, the H content of the films was lowered by replacing the N- and H-containing plasma with a N2 plasma. This was enabled by a novel three-step SiNx ALD process using Si2Cl6, CH3NH2, and N2 plasma. The three-step process lowered the H content by a factor of ~2, and the SiNx films were more conformal than films deposited using other N2-plasma-based SiNx ALD processes. Additionally, to probe the chemical differences between the planar and sidewall of Si based dielectric films deposited on high-aspect-ratio nanostructures using ALD, we designed and tested a novel transmission FTIR spectroscopy setup.","abstract_html":"The continuous shrinking of semiconductor devices beyond the current 14 nm technology node has kindled a need for the low-temperature (≤400 °C) highly-conformal (>95%) atomic layer deposition (ALD) of Si-based dielectric films for applications such as sidewall spacers in multiple patterning. In this work, we have primarily focused on understanding the surface reaction mechanisms during the ALD of Si-based dielectric films using in situ attenuated total reflection Fourier transform infrared spectroscopy. Initially, we looked at a baseline SiNx ALD process using alternating exposures of Si2Cl6 and NH3 plasma. Our infrared spectra show that H was incorporated during both half cycles in the form of –NH species, leading to a high H content and poor film quality. To improve the film quality, two approaches were considered: C incorporation and H content reduction. For the first approach, we developed and tested a framework for the incorporation of C during SiNx and SiO2 ALD to deposit SiCxNy and SiCxOy films. The framework was used to develop a novel SiCxNy ALD process using Si2Cl6 and CH3NH2 plasma. This process incorporated up to ~10% C in the form of Si–N=C=N–Si species, but H was once again incorporated during both half-cycles leading to a similar H content and film quality as the baseline SiNx ALD process. For the second approach, the H content of the films was lowered by replacing the N- and H-containing plasma with a N2 plasma. This was enabled by a novel three-step SiNx ALD process using Si2Cl6, CH3NH2, and N2 plasma. The three-step process lowered the H content by a factor of ~2, and the SiNx films were more conformal than films deposited using other N2-plasma-based SiNx ALD processes. Additionally, to probe the chemical differences between the planar and sidewall of Si based dielectric films deposited on high-aspect-ratio nanostructures using ALD, we designed and tested a novel transmission FTIR spectroscopy setup.","abstract_has_math":false,"creators":["Ovanesyan, Rafaiel A."],"institution":"Colorado School of Mines. 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In this work, we have primarily focused on understanding the surface reaction mechanisms during the ALD of Si-based dielectric films using in situ attenuated total reflection Fourier transform infrared spectroscopy. Initially, we looked at a baseline SiNx ALD process using alternating exposures of Si2Cl6 and NH3 plasma. Our infrared spectra show that H was incorporated during both half cycles in the form of –NH species, leading to a high H content and poor film quality. To improve the film quality, two approaches were considered: C incorporation and H content reduction. For the first approach, we developed and tested a framework for the incorporation of C during SiNx and SiO2 ALD to deposit SiCxNy and SiCxOy films. The framework was used to develop a novel SiCxNy ALD process using Si2Cl6 and CH3NH2 plasma. This process incorporated up to ~10% C in the form of Si–N=C=N–Si species, but H was once again incorporated during both half-cycles leading to a similar H content and film quality as the baseline SiNx ALD process. For the second approach, the H content of the films was lowered by replacing the N- and H-containing plasma with a N2 plasma. This was enabled by a novel three-step SiNx ALD process using Si2Cl6, CH3NH2, and N2 plasma. The three-step process lowered the H content by a factor of ~2, and the SiNx films were more conformal than films deposited using other N2-plasma-based SiNx ALD processes. Additionally, to probe the chemical differences between the planar and sidewall of Si based dielectric films deposited on high-aspect-ratio nanostructures using ALD, we designed and tested a novel transmission FTIR spectroscopy setup."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["born digital","doctoral dissertations"]},{"key":"dc:title","label":"Title","values":["Surface reaction mechanisms during the atomic layer deposition of silicon-based dielectrics"]}]}],"canonical_facts":{"dc:contributor.advisor":["Agarwal, Sumit"],"dc:contributor.committeemember":["Wolden, Colin Andrew","Pylypenko, Svitlana","Gomez-Gualdron, Diego A.","Hausmann, Dennis"],"dc:creator":["Ovanesyan, Rafaiel A."],"dc:date.accessioned":["2018-05-17T15:38:54Z","2022-02-03T13:14:32Z"],"dc:date.available":["2018-05-17T15:38:54Z","2022-02-03T13:14:32Z"],"dc:date.issued":["2018"],"dc:description":["Includes bibliographical references.","2018 Spring."],"dc:description.abstract":["The continuous shrinking of semiconductor devices beyond the current 14 nm technology node has kindled a need for the low-temperature (≤400 °C) highly-conformal (>95%) atomic layer deposition (ALD) of Si-based dielectric films for applications such as sidewall spacers in multiple patterning. In this work, we have primarily focused on understanding the surface reaction mechanisms during the ALD of Si-based dielectric films using in situ attenuated total reflection Fourier transform infrared spectroscopy. Initially, we looked at a baseline SiNx ALD process using alternating exposures of Si2Cl6 and NH3 plasma. Our infrared spectra show that H was incorporated during both half cycles in the form of –NH species, leading to a high H content and poor film quality. To improve the film quality, two approaches were considered: C incorporation and H content reduction. For the first approach, we developed and tested a framework for the incorporation of C during SiNx and SiO2 ALD to deposit SiCxNy and SiCxOy films. The framework was used to develop a novel SiCxNy ALD process using Si2Cl6 and CH3NH2 plasma. This process incorporated up to ~10% C in the form of Si–N=C=N–Si species, but H was once again incorporated during both half-cycles leading to a similar H content and film quality as the baseline SiNx ALD process. For the second approach, the H content of the films was lowered by replacing the N- and H-containing plasma with a N2 plasma. This was enabled by a novel three-step SiNx ALD process using Si2Cl6, CH3NH2, and N2 plasma. The three-step process lowered the H content by a factor of ~2, and the SiNx films were more conformal than films deposited using other N2-plasma-based SiNx ALD processes. Additionally, to probe the chemical differences between the planar and sidewall of Si based dielectric films deposited on high-aspect-ratio nanostructures using ALD, we designed and tested a novel transmission FTIR spectroscopy setup."],"dc:format.medium":["born digital","doctoral dissertations"],"dc:identifier":["Ovanesyan_mines_0052E_11474.pdf","T 8473"],"dc:identifier.uri":["https://hdl.handle.net/11124/172268"],"dc:language":["English"],"dc:language.iso":["eng"],"dc:publisher":["Colorado School of Mines. Arthur Lakes Library"],"dc:rights":["Copyright of the original work is retained by the author."],"dc:subject":["dielectrics","silicon","atomic layer deposition","surface science","infrared spectroscopy"],"dc:title":["Surface reaction mechanisms during the atomic layer deposition of silicon-based dielectrics"],"dc:type":["Text"],"thesis:degree_discipline":["Chemical and Biological Engineering"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Doctor of Philosophy (Ph.D.)"],"thesis:institution_name":["Colorado School of Mines"]},"updated_at":"2026-07-24T01:42:56Z"}