HIGH FREQUENCY DIELECTRIC PROPERTIES OF POLYIMIDES FOR MULTILAYER INTERCONNECT STRUCTURES
AuthorHinedi, Mohamad Fahd, 1964-
KeywordsPolyimides -- Electric properties.
Polyimides -- Thermal properties.
Very high speed integrated circuits -- Materials -- Electric properties.
Very high speed integrated circuits -- Materials -- Thermal properties.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractOne of the most important electrical requirements in high performance electronic systems or high speed integrated circuits, is to process larger numbers of electrical signals at much higher speeds. Signal propagation delay must be minimized in order to maximize signal velocities. Therefore, material with low dielectric constant and low dissipation factor is being sought. In this thesis research measurements of dielectric constant and dissipation factor were performed on commercially available polyimides that are used in multilayer interconnect structures. Capacitor structures with a polyimide dielectric were measured up to a 1GHz frequency and 220°C temperature. Polyimides were concluded to be compatible for use in high performance systems such as multilayer interconnect structures.
Degree ProgramGraduate College
Electrical and Computer Engineering
Degree GrantorUniversity of Arizona
Showing items related by title, author, creator and subject.
Investigation of relations between the geometrical properties and hydraulic properties of jointed rock through numerical simulation.Panda, Bibhuti Bhusan.; Kulatilake, P. H. S. W.; Glass, Charles E.; Lever, Paul J.A.; Contractor, Dinshaw N. (The University of Arizona., 1995)Effect of joint geometry parameters and joint transmissivity on the hydraulic properties of jointed rock including the equivalent permeability tensor is investigated through a series of numerical experiments. The equivalent continuum hydraulic behavior of jointed rock was found to be sensitive to the orientation of the joint sets in a joint network system. The chances for the equivalent continuum behaviour were found to increase with the increase of joint density and joint size. It was found that for some joint systems, the equivalent continuum behavior does not exist irrespective of the rock block size; joint systems with low orientation angles, low joint densities and small joint sizes seem to have chance belonging to this category. The equivalent continuum behavior of a joint system can be expressed with respect to a cut-off value for the first invariant of fracture tensor (F0). If the F0 value for a given joint network is more than the cut-off value, then the joint system can be approximated by an equivalent continuum. For the joint systems investigated in this study, values between 10 and 30 were found for cut-off F0. A threshold value of F0 between 3 and 6 was found to achieve a non-zero average block permeability (K0). Both the threshold value and the cut-off value of F0 were found to depend on the relative orientations of joint sets. Chances to reach equivalent continuum behavior for a rock mass having a certain joint configuration increases with the increase of block size. REV size for a joint system was found to depend on the orientation of the joint sets and on the distribution of joint size and density. REV size seems to decrease with increasing joint density. The block size corresponding to the aforementioned cut-off F0 can be considered to provide the REV size for a given joint configuration. For a considered joint network, K0 increases with the increase of block size until the block size is equal to REV size. The K0 value at the REV size for a joint system increases with increase in joint size and joint density. The relation between K0 and F0 seems to depend on the relative orientation of the joint sets in the joint network. Joint hydraulic conductivity plays a major role on the equivalent continuum behaviour and permeability anisotropy. A non linear relation seems to exist between the directional permeability and the fracture tensor component for the connected joint configuration when rock blocks contain minor discontinuities. For rock blocks containing major discontinuities this relation becomes linear.
Thermophysical Properties of the North Polar Residual Cap using Mars Global Surveyor Thermal Emission SpectrometerBapst, J.; Byrne, S.; Bandfield, J. L.; Hayne, P. O.; Univ Arizona, Lunar & Planetary Lab (AMER GEOPHYSICAL UNION, 2019-05)Using derived temperatures from thermal-infrared instruments aboard orbiting spacecraft, we constrain the thermophysical properties, in the upper few meters, of the north polar residual cap of Mars. In line with previous authors we test a homogeneous thermal model (i.e., depth-independent thermal properties), simulating water ice of varying porosity against observed temperatures. We find that high thermal inertia (>1,000Jm(-2)K(-1)s(1/2) or <40% porosity) provides the best fit for most of the residual cap. Additionally, we test the observed data against models with depth-dependent thermal properties. Models tested converge on similar solutions: we find extensive regions of low surface thermal inertia consistent with a porous layer at the surface (>40% porosity) that densifies with depth into a zero-porosity ice layer at shallow depths (<0.5m). We interpret this as evidence of recent water ice accumulation. Our results along the edge of the residual cap imply that denser (<40% porosity) ice is present at the surface and coincides with lower albedo. These results suggest that older ice is undergoing exhumation along much of the residual cap margin. The results support recent water ice accumulation having occurred over specific regions, while ablation dominates in others. Plain Language Summary The polar regions of Mars host kilometer-thick stacks of water ice that have been built up over millions of years. At the north pole today, the top of this ice deposit is interacting with the Martian atmosphere. Whether or not ice at the surface is fluffy (like snow) or dense (like an ice slab) can provide useful information about the polar ice cap and recent climate. Multiple years of surface temperature measurements have been acquired by instruments aboard spacecraft in orbit around Mars. By comparing these values with temperature simulations, we can narrow down the type of ice near the surface. Our results show that the type of ice varies across the polar cap. Some regions appear to be a snow-like surface where the polar cap may be growing. Other regions, most notably along the edge of the polar cap, show denser ice that is likely older. The nature of the ice tells us about the current climate and how these kilometer-thick ice deposits form.
Macrofiber properties of the Bacillus subtilis strain carrying a transposon insertionSu, Ling-Ing, 1961- (The University of Arizona., 1990)Recently, a new strain of B. subtilis (Bull913) carrying Tn917, a Streptococcus-derived transposon that confers erythromycin and lincomycin resistance, in the host chromosome has been isolated that grows as multistrand helical structures. Bull913 can produce macrofibers whose properties are like another B. subtilis strain FJ7. FJ7 is a lyt-2 mutant produced by chemical mutagenesis which can form macrofibers with twists ranging from right to left handed. Bull913 also has this spectrum of twisted states. Bull913 macrofibers are similar to FJ7 but are longer lived than FJ7. The Macrofiber properties of Bull913 were compared to FJ7 using growth in liquid media supplemented with (NH₄)₂SO₄ or MgSO₄ -- conditions giving LH or RH macrofibers, respectively for FJ7. The autolysin activities and cell walls substrate properties of Bull913 were biochemically analyzed and compared to those of strains 168 and FJ7. Polyacrylamide gel electrophoresis (PAGE) was used to compare the wall proteins from all three strains. Finally, genetic studies of Bull913 were carried out to determine if the defect in Bull913 is in the lyt-1, lyt-2 or lyt-15 genes, or in a new gene. Both biochemical analysis and genetic studies suggest that Bul1913 carries Tn917 in the lyt-2 gene.