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HfO2 Film (hfo2 + film)
Selected AbstractsAtomic Layer Deposition of High- k Oxides of the Group 4 Metals for Memory Applications (Adv. Eng.ADVANCED ENGINEERING MATERIALS, Issue 4 2009Mater. The cover shows high temperature XRD patterns of a 5.8 nm thick HfO2 film and 7.3 nm yttrium-doped HfO2 grown by atomic layer deposition (ALD). More details can be found in the article of J. Niinistö et al. where recent development in ALD of high-k dielectric oxides for memory applications is reviewed on page 223. [source] Observation of interfacial electrostatic field-induced changes in the silicon dielectric function using spectroscopic ellipsometryPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2008J. Price Abstract This work investigates the capability of spectroscopic ellipsometry to measure charge trapping centers in thin dielectric films. Specific interfacial electrostatic fields, induced by electrons injected into charge trapping states at the interface, have been identified that directly affect the underlying silicon substrate critical points. The effect of a field-induced change in the silicon fundamental absorption edge due to different processing conditions affecting the oxygen vacancy defects at the interface is presented. Measuring the field-induced change in the silicon dielectric function between a sample with a 2 nm HfO2 film as-deposited and the same sample after a 1000 °C anneal in an N2 ambient reveals that a stronger interfacial field is present for the as-deposited HfO2 film. These results are consistent with the understanding that high temperature anneals work well to passivate oxygen vacancy defects at the silicon/HfO2 interface. Finally, we compare our results with Second Harmonic Generation where specific resonant features are identifiable with electric field enhancements at the same interface. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Investigation of top gate electrode options for high-k gate dielectric MOS capacitorsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008D. C. Moschou Abstract Capacitors with a high-k HfO2 film as gate dielectric were fabricated, using three different variations for the top gate electrode. This way it was possible to acquire important information on which kind of gate material should be used in combination with HfO2 as a gate insulator for optimum performance of possible low temperature applications, such as high-k TFTs. The variations of gate electrode were e-gun evaporated Al, sputtered W and CVD polysilicon followed by ion implantation and annealing. The capacitors were then characterized with capacitance-voltage measurements and current-voltage measurements. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Heteroleptic Guanidinate- and Amidinate-Based Complexes of Hafnium as New Precursors for MOCVD of HfO2EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2010Ke Xu Abstract The synthesis and characterization of four new heteroleptic complexes [Hf{,2 -(iPrN)2CNMe2}2Cl2] (1), [Hf{,2 -(iPrN)2CNMe2}2Me2] (2), [Hf{,2 -(iPrN)2CMe}2Cl2] (3), and [Hf{,2 -(iPrN)2CMe}2Me2] (4) are reported. All the complexes were characterized by spectroscopic methods, while compounds 1,3 were further examined by single-crystal X-ray diffraction, revealing that the complexes are monomers with the hafnium center in a distorted octahedral geometry. The thermal properties of the chlorine-free complexes (2, 4) were examined to determine their suitability for metalorganic chemical vapor deposition (MOCVD) applications, and compound 2 showed good volatility and thermal stability. On the basis of these results, compound 2 was selected for MOCVD of HfO2 with oxygen as oxidant. Depositions were carried out on Si(100) substrates in the temperature range 300,700 °C. The as-deposited HfO2 films crystallized in the monoclinic phase at temperatures above 500 °C, and the composition analysis determined by Rutherford back-scattering (RBS) and X-ray photoelectron spectroscopy (XPS) revealed that the films were stoichiometric and free of carbon. Thus, alkylguanidinatohafnium complex 2 is a promising precursor for growing HfO2 films in a wide temperature range with the desired stoichiometry, because of its adequate volatility, sufficient temperature window between vaporization and decomposition, as well as its ability to decompose cleanly in the presence of oxygen. [source] Optical properties of MOCVD HfO2 filmsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2009Boris Ayupov Abstract Hafnium(IV) 2,2,6,6-tetramethylheptane-3,5-dionate Hf(thd)4 was used for depositing HfO2 coatings by MOCVD in vertical reactor in different conditions. Monochromatic null ellipsometry was applied to characterize the film thickness and refractive index using different optical model of samples. The definition of sample optical anisotropy points to the growth of HfO2 nanocrystals during film annealing. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||