Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications

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dc.contributor.advisor Angus Kingon, Committee Chair en_US
dc.contributor.advisor Gregory Parsons, Committee Member en_US
dc.contributor.advisor Jon-Paul Maria, Committee Member en_US
dc.contributor.advisor Mark Johnson, Committee Member en_US
dc.contributor.author Jur, Jesse Stephen en_US
dc.date.accessioned 2010-04-02T19:14:03Z
dc.date.available 2010-04-02T19:14:03Z
dc.date.issued 2007-07-27 en_US
dc.identifier.other etd-06282007-143330 en_US
dc.identifier.uri http://www.lib.ncsu.edu/resolver/1840.16/5447
dc.description.abstract The ability to improve performance of the high-end metal oxide semiconductor field effect transistor (MOSFET) is highly reliant on the dimensional scaling of such a device. In scaling, a decrease in dielectric thickness results in high leakage current between the electrode and the substrate by way of direct tunneling through the gate dielectric. Observation of a high leakage current when the standard gate dielectric, SiO2, is decreased below a thickness of 1.5 nm requires engineering of a replacement dielectric that is much more scalable. This high- dielectric allows for a physically thicker oxide, reducing leakage current. Integration of select lanthanide-based oxides and silicates, in particular lanthanum oxide and silicate, into MOS gate stack devices is examined. The quality of the high-K dielectrics is monitored electrically to determine properties such as equivalent oxide thickness, leakage current density and defect densities. In addition, analytical characterization of the dielectric and the gate stack is provided to examine the materialistic significance to the change of the electrical properties of the devices. It is shown that optimization of low-temperature processing can result in MOS devices with an equivalent oxide thickness (EOT) as low 5 Å and a leakage current density of 5.0 A⁄cm2. High-temperature processing, consistent with a MOSFET source-drain activation anneal, yields MOS devices with an EOT as low as 1.1 nm after optimization of the TaN/W electrode properties. The decrease in the device effective work function (phi_M,eff) observed in these samples is examined in detail. First, as a La2O3 capping layer on HfSiO(N), the shift yields ideal-phi_M,eff values for nMOSFET deices (4.0 eV) that were previously inaccessible. Other lanthanide oxides (Dy, Ho and Yb) used as capping layers show similar effects. It is also shown that tuning of phi_M,eff can be realized by controlling the extent of lanthanide-silicate formation. This research, conducted in conjunction with SEMATECH and the SRC, represents a significant technological advancement in realizing 45 and sub-45 nm MOSFET device nodes. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject dc magnetron sputtering en_US
dc.subject physical vapor deposition en_US
dc.subject tungsten oxide en_US
dc.subject tungsten en_US
dc.subject W en_US
dc.subject tantalum nitride en_US
dc.subject TaN en_US
dc.subject lanthanum en_US
dc.subject lanthanum oxide en_US
dc.subject La en_US
dc.subject La2O3 en_US
dc.subject La2SiO5 en_US
dc.subject lanthanum silicate en_US
dc.subject La2Si2O7 en_US
dc.subject Ho en_US
dc.subject holmium en_US
dc.subject holmium oxide en_US
dc.subject cation diffusion en_US
dc.subject back-side SIMS en_US
dc.subject secondary ion mass spectroscopy en_US
dc.subject SIMS en_US
dc.subject XRD en_US
dc.subject x-ray diffraction en_US
dc.subject molecular beam deposition en_US
dc.subject PMA en_US
dc.subject XPS en_US
dc.subject x-ray photoemission spectroscopy en_US
dc.subject post metallization anneal en_US
dc.subject RCA en_US
dc.subject chemical oxide en_US
dc.subject metal oxide semiconductor field effect transistor en_US
dc.subject MBE en_US
dc.subject silica en_US
dc.subject SiO2 en_US
dc.subject interfacial layer en_US
dc.subject gate dielectric en_US
dc.subject dielectric en_US
dc.subject silicate en_US
dc.subject oxide en_US
dc.subject high-kappa en_US
dc.subject EOT en_US
dc.subject equivalent oxide thickness en_US
dc.subject high-k en_US
dc.subject band diagram en_US
dc.subject valance band offset en_US
dc.subject conduction band offset en_US
dc.subject band gap energy en_US
dc.subject effective work function en_US
dc.subject work function en_US
dc.subject voltage shift en_US
dc.subject threshold voltage en_US
dc.subject flat band voltage en_US
dc.subject leakage current en_US
dc.subject capacitance en_US
dc.subject mobility en_US
dc.subject electronic materials en_US
dc.subject scaling en_US
dc.subject Moore?s Law en_US
dc.subject MIS en_US
dc.subject MOS en_US
dc.subject MOSFET en_US
dc.subject high resolution transmission electron microscopy en_US
dc.subject HRTEM en_US
dc.subject RTA en_US
dc.subject rapid thermal anneal en_US
dc.subject PVD en_US
dc.subject tantalum en_US
dc.subject Ta en_US
dc.subject gate electrode en_US
dc.subject metal electrode en_US
dc.subject hafnium silicate en_US
dc.subject hafnium oxide en_US
dc.subject hafnium en_US
dc.subject ytterbium en_US
dc.subject ytterbium oxide en_US
dc.subject Yb en_US
dc.subject dysprosium oxide en_US
dc.subject dysprosium en_US
dc.subject Dy en_US
dc.subject E-beam evaporation en_US
dc.subject thermal evaporation en_US
dc.subject forming gas anneal en_US
dc.subject ozone en_US
dc.subject ammonia anneal en_US
dc.subject FGA en_US
dc.title Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications en_US
dc.degree.name PhD en_US
dc.degree.level dissertation en_US
dc.degree.discipline Materials Science and Engineering en_US


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