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dcterms.accessRightsAccess limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan through a local library, pending author/copyright holder's permission.
dc.contributor.advisorGougousi, Theodosia
dc.contributor.departmentPhysics
dc.contributor.programPhysics, Applied
dc.creatorHackley, Justin
dc.date.accessioned2015-10-14T03:13:33Z
dc.date.available2015-10-14T03:13:33Z
dc.date.issued2008-09-26
dc.description.abstractAtomic layer deposition (ALD) is a cyclic growth process that is distinguished by a self-limiting, two-step surface reaction that results in precise growth control and high quality, conformal thin films. Due to the continuous downscaling of MOSFET devices, a large interest has recently developed in the ALD of high- ? dielectric materials as gate oxide layers on Si and III-V substrates. The ALD of HfO2 is an established process; however, there is still controversy over the initial growth mechanisms on differently prepared Si surfaces. This motivated a comparison of the nucleation stage of HfO2 films grown on OH- (Si-OH) and H-terminated (Si-H) Si(100) surfaces. Two different ALD chemistries are investigated, including tetrakis[ethylmethylamino]hafnium (Hf[N(CH3)(C2H5)]4), abbreviated as TEMAH, and tetrakis[dimethylamino]hafnium (Hf[N(CH3)2]4, abbreviated as TDMAH. H2O is used as the oxidizing precursor. Deposition temperatures of 250-275°C result in a linear growth per cycle of 1 Å/cycle. Techniques including Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), and transmission electron microscopy are used to examine the film interface and initial film growth. HfO2 films are also subjected to post-deposition anneals, and the film morphology is examined with X-ray diffraction, Fourier transform infrared spectroscopy and atomic force microscopy. GaAs MOSFET devices have long proven elusive due to the lack of a stable native oxide. Recent research into high- ? dielectric materials for use in Si-based devices has presented many new options for insulating layers on GaAs. HfO2 growth on GaAs(100) from a TDMAH+H2O ALD process is studied here. Three different GaAs surface treatments are examined, including buffered oxide etch (BOE), NH4OH, and a simple acetone/methanol wash (to retain the native oxide surface). Initial HfO2 growth on these surfaces is characterized with RBS and SE. The interfacial composition is examined with XPS both before and after HfO2 deposition. Also, an interesting native oxide 'consumption' mechanism is investigated, which involves the dissolution of the GaAs native oxide during the ALD process. This project presents the first detailed study of HfO2 growth on GaAs with the TDMAH/H2O ALD chemistry, providing XPS, RBS and SE characterization of early film growth.
dc.formatapplication/pdf
dc.genredissertations
dc.identifierdoi:10.13016/M2J95M
dc.identifier.other1281
dc.identifier.urihttp://hdl.handle.net/11603/1062
dc.languageen
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Theses and Dissertations Collection
dc.relation.ispartofUMBC Graduate School Collection
dc.relation.ispartofUMBC Student Collection
dc.relation.ispartofUMBC Physics Department Collection
dc.rightsThis item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu.
dc.sourceOriginal File Name: umi-umbc-1281.pdf
dc.subjectPhysics, General (0605)
dc.titleInitial HfO2 Growth on Si(100) and GaAs(100) Substrates using TEMAH+H2O and TDMAH+H2O ALD Processes
dc.typeText


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