Mehmet Çopuroğlu

Capacitance and

This paper presents a method for measuring the complex permittivity of a dielectric material on a dielectric/metal stack without etching the dielectric layer. A series of circular capacitor test structures were designed and fabricated. For the first time, the unwanted capacitance Cp, which is formed by the oxide layer between the bottom metal layer and the silicon substrate, was defined and systematically investigated. The technique is shown to be suitable for characterization of a lead magnesium niobate-lead titanate (PMNT) material on the complex cross sections involved in the development of a novel high-k material. An extremely high- k of 1115 (high capacitance density of 26 fF/μm2) for a PMNT metal-insulator-metal (MIM) capacitor was achieved. In addition, low leakage current density of 2 × 10-10 A/cm2 and low loss tangent were also obtained. These results clearly showed that the PMNT MIM capacitors are very promising for both decoupling and more general RF and mixed-signal applications until the year 2020, according to the International Technology Roadmap for Semiconductors (ITRS).

S

A Pb(Mg0.33Nb0.67)0.65Ti0.35O3 material system was synthesized by the sol-gel method; thin films were deposited via the spin-coating technique, and processed using the rapid thermal annealing. Effects of preparation parameters, such as annealing temperature and atmosphere, on the phase composition, microstructure and electrical properties were identified. Morphologically uniform and crack-free films were obtained. Among the obtained films, the highest k value was found to be 1425 for the 380 nm thick film that was annealed at 750 °C in O2 indicating the suitability of this material system for ultrahigh-value capacitor applications.

-Parameter Techniques for Dielectric Characterization With Application to High-

This paper presents the systematic investigation by electrical characterization of PMNT (lead magnesium niobate - lead titanate, Pb(Mg_0.33Nb_0.67)_0.65Ti_0.35O₃) thin-films with different fabrication parameters. The PMNT thin-films are processed under different conditions including annealing at various temperatures. Capacitance-voltage (C-V), current-voltage (I-V), capacitance-frequency (C-F), dissipation factor-frequency (D-F) and complex impedance-frequency (Z-F) measurements are presented.

k

Abstract This article presents and discusses the preliminary results obtained as a continuation of a work aiming to contribute to the effort of exploring the potential of certain types of polymer nanocomposites to be successful candidates in new fields such as dental restoration. An epoxy-functional silicate-/Zr-based polymeric nanocomposite material system containing phosphorus was obtained via a sol–gel method, and applied to bring about a bonding between bovine teeth and feldspathic ceramic discs with or without the use of visible light (VL)-curing process. Infrared spectroscopy was employed to show the presence of phosphorus within the structure. Mechanical tests were performed to determine the shear-bond strength of the nanocomposite adhesive system developed. An approximate shear-bond strength value of 0.4 MPa was obtained for both VL-cured and uncured systems. Though this value was lower than that of commercially available material systems, it was promisingly comparable to them. Another significant finding was that the material system developed within the study might potentially eliminate the use of curing process. Also, it was demonstrated that the general problem of ‘shrinkage-upon-polymerization’ could be overcome by use of a polymeric nanocomposite adhesive material system of this type. Overall results indicated that this polymeric nanocomposite system could indeed be potentially considered as an adhesive alternative in prospective dental restoration applications.

PMNT Thin-Film Layers

Abstract Abstract A near morphotropic phase boundary lead–magnesium–niobium titanate material system was synthesised by the sol–gel method; its thin films were deposited with or without nanoparticle (np) seeding and processed by the rapid thermal annealing. Influences of some process parameters and the np seeding on various properties of the resultant films were systematically investigated. Although no reduction in annealing temperature was achieved upon np seeding, the results indicated that nps might indeed play a role as nucleation centres during the crystallisation. All in all, the lead–magnesium–niobium titanate thin film system described here (particularly those annealed at higher temperatures) appeared to be suitable for its potential applications in wireless communication systems as ultrahigh dielectric constant ϵ value capacitors; the unexposed film annealed at 750°C, for instance, exhibited the highest dielectric constant ϵ (1425) with a low loss (loss tangent, ∼0·04) along with a strongly pronounced perovskite phase (96·5%).

Sol-gel-derived lead-magnesium-niobium titanate thin films for ultrahigh-value capacitor applications

In order to extract the dielectric properties of high-k PMNT material, a series of test structures are designed and fabricated. Thin-film characterisation through wafer-probe measurements and electromagnetic simulation are presented. An efficient extraction approach is presented to extract the dielectric constant (r) of insulator materials up to 6 GHz. The technique works by comparing the propagation constant, γ, extracted from S-parameter measurements and electromagnetic simulations, respectively. The extracted r of the typical PMNT material is 950.