The development of novel reactive sputtering methods in the study of strontium bismuth tantalate

Persistent Link:
http://hdl.handle.net/10150/280186
Title:
The development of novel reactive sputtering methods in the study of strontium bismuth tantalate
Author:
Hilliard, Donald Bennett
Issue Date:
2002
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Contrary to the claims of numerous reports over the last two decades, there does not yet exist a viable plasma sputtering method for complex oxides such as the lead- and bismuth-containing perovskites. In fact, the lack of reproducibility in any vapor deposition means for such materials is the primary reason why the promise of nonvolatile ferroelectric RAM (FeRAM) has delivered so little over the last two decades, with only low-density devices being provided, instead, by solution and mist techniques (via both sol-gel and MOD). In part, the present work provides the first comprehensive treatment of the challenges present in the plasma sputter deposition of ferroelectric strontium bismuth tantalate (SBT), with SBT thin films fabricated under a wide variety of deposition approaches. As such, ferroelectric SBT was successfully formed by the primary plasma sputtering methods used for ferroelectric materials in the past; namely, R.F. sputtering of ceramic targets and D.C. reactive sputtering of metal targets. Capacitors were fabricated to establish the ferroelectric properties of the SBT films. The approach allows for new insights into phase formation in the SBT system. The inadequacies of the previous sputtering approaches used for ferroelectrics (as well as High Tc superconductors) are highlighted in the context of their inherent run-to-run instability. Subsequently, there is developed a new and rather fundamental vapor deposition technique, termed Electron-Assisted Deposition (EAD), which provides uniquely non-equilibrium growth conditions. This terminology is founded in the direct contradistinction of the presently developed process with previously developed Ion-Assisted Deposition (IAD) processes. The developed EAD process provides the first means by which metallic-mode reactive sputtering, wherein the desired compound is formed by surface reactions at the film's growth interface, can be implemented for a ferroelectric or, in fact, the multicomponent perovskites, in general. In addition to other benefits, such metallic-mode sputtering is found to be inherently more stable and reproducible than the previously used ceramic-target and poisoned-target approaches.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Materials Science.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Materials Science and Engineering
Degree Grantor:
University of Arizona
Advisor:
Jackson, Kenneth A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleThe development of novel reactive sputtering methods in the study of strontium bismuth tantalateen_US
dc.creatorHilliard, Donald Bennetten_US
dc.contributor.authorHilliard, Donald Bennetten_US
dc.date.issued2002en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractContrary to the claims of numerous reports over the last two decades, there does not yet exist a viable plasma sputtering method for complex oxides such as the lead- and bismuth-containing perovskites. In fact, the lack of reproducibility in any vapor deposition means for such materials is the primary reason why the promise of nonvolatile ferroelectric RAM (FeRAM) has delivered so little over the last two decades, with only low-density devices being provided, instead, by solution and mist techniques (via both sol-gel and MOD). In part, the present work provides the first comprehensive treatment of the challenges present in the plasma sputter deposition of ferroelectric strontium bismuth tantalate (SBT), with SBT thin films fabricated under a wide variety of deposition approaches. As such, ferroelectric SBT was successfully formed by the primary plasma sputtering methods used for ferroelectric materials in the past; namely, R.F. sputtering of ceramic targets and D.C. reactive sputtering of metal targets. Capacitors were fabricated to establish the ferroelectric properties of the SBT films. The approach allows for new insights into phase formation in the SBT system. The inadequacies of the previous sputtering approaches used for ferroelectrics (as well as High Tc superconductors) are highlighted in the context of their inherent run-to-run instability. Subsequently, there is developed a new and rather fundamental vapor deposition technique, termed Electron-Assisted Deposition (EAD), which provides uniquely non-equilibrium growth conditions. This terminology is founded in the direct contradistinction of the presently developed process with previously developed Ion-Assisted Deposition (IAD) processes. The developed EAD process provides the first means by which metallic-mode reactive sputtering, wherein the desired compound is formed by surface reactions at the film's growth interface, can be implemented for a ferroelectric or, in fact, the multicomponent perovskites, in general. In addition to other benefits, such metallic-mode sputtering is found to be inherently more stable and reproducible than the previously used ceramic-target and poisoned-target approaches.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Materials Science.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorJackson, Kenneth A.en_US
dc.identifier.proquest3073232en_US
dc.identifier.bibrecord.b43471961en_US
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