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You searched for subject:(Hafnium Silicate). Showing records 1 – 2 of 2 total matches.

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North Carolina State University

1. Hong, Joon Goo. Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps.

Degree: PhD, Materials Science and Engineering, 2003, North Carolina State University

Aggressive scaling of devices has continued to improve MOSFET transistor performance. As lateral device dimensions continue to decrease, gate oxide thickness must be scaled down. As one of the promising high k gate oxide material, HfO₂ and its silicates were investigated to understand their direct tunneling behavior by studying conduction and valence band offset energies with spectroscopy and electrical characterization. Local bonding change of remote plasma deposited (HfO₂)[subscript x](SiO[subscript 8322;)[subscript 1-x] alloys were characterized by Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES) as a function of alloy composition, x. Two different precursors with Hf Nitrato and Hf-tert=butoxide were tested to have amorphous deposition. Film composition was determined off-line by Rutherford backscattering spectroscopy (RBS) and these results were calibrated with on-line AES. As deposited Hf-silicate alloys were characterized by off-line XPS and AES for their chemical shifts interpreting with a partial charge transfer model as well as coordination changes.Sigmoidal dependence of valence band offse energies was observed. Hf 5d state is fixed at the bottom of the conduction band and located at 1.3 ± 0.2 eV above the top of the Si conduction band as a conduction band offset by x-ray absorption spectroscopy (XAS). Optical band gap energy changes were observed with vacuum ultra violet spectroscopic ellipsometry (VUVSE) to verify compositional dependence of conduction and valence band offset energy changes. 1 nm EOT normalized tunneling current with Wentzel-Kramer-Brillouin (WKB) simulation based on the band offset study and Franz two band model showed the minimum at the intermediate composition matching with the experimental data. Non-linear trend in tunneling current was observed because the increases in physical thickness were mitigated by reduction in band offset energies and effective mass for tunneling. C-V curves were compared to each other, and more hysteresis was observed with increasing x. Localized Hf 5d state as a trap site was the reason for hysteresis and its reverse direction with temperature-dependent C-V curves. Temperature-dependent I-V study located Hf 5d state. For the integration issue, nitridation study was performed at the interface, surface and both. Interfacial nitridation gave more effective reduction in EOT. Advisors/Committee Members: Gerald Lucovsky, Committee Chair (advisor), Carlton Osburn, Committee Member (advisor), Gerd Duscher, Committee Member (advisor), Klaus Bachmann, Committee Member (advisor).

Subjects/Keywords: RPE-CVD. MOCVD; local bond; FTIR; Poole-Frenkel; nitridation; temperature dependent CV; IV; CV; electrical property; transition metal oxide; Optical Band Gap; Valence band; Conduction band; Hafnium Silicate; Spectroscopy; High k gate oxide

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hong, J. G. (2003). Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/2978

Chicago Manual of Style (16th Edition):

Hong, Joon Goo. “Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps.” 2003. Doctoral Dissertation, North Carolina State University. Accessed September 26, 2020. http://www.lib.ncsu.edu/resolver/1840.16/2978.

MLA Handbook (7th Edition):

Hong, Joon Goo. “Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps.” 2003. Web. 26 Sep 2020.

Vancouver:

Hong JG. Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps. [Internet] [Doctoral dissertation]. North Carolina State University; 2003. [cited 2020 Sep 26]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2978.

Council of Science Editors:

Hong JG. Spectroscopic Study of Hafnium Silicate Alloys prepared by RPECVD: Comparisons between Conduction/Valence Band Offset Energies and Optical Band Gaps. [Doctoral Dissertation]. North Carolina State University; 2003. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2978


North Carolina State University

2. Jur, Jesse Stephen. Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications.

Degree: PhD, Materials Science and Engineering, 2007, North Carolina State University

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. Advisors/Committee Members: Angus Kingon, Committee Chair (advisor), Gregory Parsons, Committee Member (advisor), Jon-Paul Maria, Committee Member (advisor), Mark Johnson, Committee Member (advisor).

Subjects/Keywords: dc magnetron sputtering; physical vapor deposition; tungsten oxide; tungsten; W; tantalum nitride; TaN; lanthanum; lanthanum oxide; La; La2O3; La2SiO5; lanthanum silicate; La2Si2O7; Ho; holmium; holmium oxide; cation diffusion; back-side SIMS; secondary ion mass spectroscopy; SIMS; XRD; x-ray diffraction; molecular beam deposition; PMA; XPS; x-ray photoemission spectroscopy; post metallization anneal; RCA; chemical oxide; metal oxide semiconductor field effect transistor; MBE; silica; SiO2; interfacial layer; gate dielectric; dielectric; silicate; oxide; high-kappa; EOT; equivalent oxide thickness; high-k; band diagram; valance band offset; conduction band offset; band gap energy; effective work function; work function; voltage shift; threshold voltage; flat band voltage; leakage current; capacitance; mobility; electronic materials; scaling; Moore?s Law; MIS; MOS; MOSFET; high resolution transmission electron microscopy; HRTEM; RTA; rapid thermal anneal; PVD; tantalum; Ta; gate electrode; metal electrode; hafnium silicate; hafnium oxide; hafnium; ytterbium; ytterbium oxide; Yb; dysprosium oxide; dysprosium; Dy; E-beam evaporation; thermal evaporation; forming gas anneal; ozone; ammonia anneal; FGA

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jur, J. S. (2007). Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/5447

Chicago Manual of Style (16th Edition):

Jur, Jesse Stephen. “Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications.” 2007. Doctoral Dissertation, North Carolina State University. Accessed September 26, 2020. http://www.lib.ncsu.edu/resolver/1840.16/5447.

MLA Handbook (7th Edition):

Jur, Jesse Stephen. “Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications.” 2007. Web. 26 Sep 2020.

Vancouver:

Jur JS. Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications. [Internet] [Doctoral dissertation]. North Carolina State University; 2007. [cited 2020 Sep 26]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5447.

Council of Science Editors:

Jur JS. Lanthanide-based Oxides and Silicates for High-K Gate Dielectric Applications. [Doctoral Dissertation]. North Carolina State University; 2007. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5447

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