Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Article Citation - WoS: 18Citation - Scopus: 20Impact of Incorporated Oxygen Quantity on Optical, Structural and Dielectric Properties of Reactive Magnetron Sputter Grown High-? Hfo2/Hf Thin Film(Elsevier Ltd., 2014) Cantaş, Ayten; Aygün, Gülnur; Turan, RaşitHigh-κ hafnium-oxide thin films have been fabricated by radio frequency (rf) reactive magnetron sputtering technique. To avoid formation of an undesired interfacial suboxide layer between Si and high-κ film, prior to HfO2 deposition, a thin Hf buffer layer was deposited on p-type (1 0 0) Si substrate at room temperature. Effect of oxygen gas quantity in the O2/Ar gas mixture was studied for the optical and structural properties of grown HfO2 high-κ thin films. The grown thin oxide films were characterized optically using spectroscopic ellipsometer (SE) in detail. Crystal structure was studied by grazing incidence X-ray diffractometer (GIXRD) technique, while bonding structure was obtained by Fourier transform infrared spectroscopy (FTIR) analyses. In agreement with GIXRD and FTIR analyses, SE results show that any increment above ideal quantity of oxygen content in the gas mixture resulted in decrements in the refractive index and thickness of HfO2 dielectric film, while increments in SiO2 thickness. It is apparent from experimental results that oxygen to argon gas ratio needs to be smaller than 0.2 for a good film quality. The superior structural and optical properties for grown oxide film were obtained for O2/Ar gas ratio of about 0.05-0.1 combined with ∼30 W constant rf sputtering power. © 2014 Elsevier B.V. All rights reserved.Article Citation - WoS: 14Citation - Scopus: 18Xps Study of Pulsed Nd:yag Laser Oxidized Si(Elsevier Ltd., 2006) Özyüzer, Gülnur Aygün; Aygün, Gülnur; Atanassova, Elenada A.; Kostov, K.; Turan, RaşitX-ray photoelectron spectra (XPS) of thin SiO2 layers grown by pulsed Nd:YAG laser at a substrate temperature of 748 K are presented. The peak decomposition technique combined with depth profiling is employed to identify the composition and chemical states of the film structure. It is established that the oxide is non-stoichiometric, and contains all oxidation states of Si in different amounts throughout the film. The interface Si/laser-grown oxide is not abrupt, and the coexistence of Si2O3 and Si2O suboxides in a relatively wide interfacial region is found. It is concluded that post-oxidation annealing is necessary in order to improve the microstructure of both oxide and near interface region.