Engineering Commons^™

Secondary Electron Imaging Of Embedded Defects In Carbon Nanofiber Via Interconnects, Makoto Suzuki, Yusuke Ominami, Takashi Sekiguchi, Cary Y. Yang

Electrical and Computer Engineering

Carbon nanofiber (CNF) via interconnect test structures are fabricated with the bottom-up process proposed by Li et al. [Appl. Phys. Lett. 82, 2491 (2003)] for next-generation integrated circuit technology. Critical defects in the interconnect structure are examined using scanning electron microscopy. It is shown that secondary electron signal with optimized incident beam energy is useful for detecting embedded defects, including unexposed CNF plugs and voids in the dielectric layer. The defect imaging mechanisms are elucidated based on beam-induced charging of the specimen surface.

Secondary Electron Emission From Freely Supported Nanowires, Makoto Suzuki, Kazuhiro Kumagai, Takashi Sekiguchi, Alan M. Cassell, Tsutomu Saito, Cary Y. Yang

Electrical and Computer Engineering

We present secondary electron (SE) emission results from freely supported carbon/silicon nitride (Si₃N₄) hybrid nanowires using scanning electron microscopy. We found that, contrary to bulk materials, the SE emission from insulating or electrically isolated metallic nanowires is strongly suppressed by the penetrating beam. A mechanism of the SE suppression by the positive specimen charging is proposed, which is based on a total emission yield calculation using the Monte Carlo technique. This finding provides an important basis for studying low-energy electron emission from nanostructures under a penetrating electron beam.

Numerical Simulation Of Thermo-Elasticity, Inelasticity And Rupture Inmembrane Theory, Michael Taylor

Mechanical Engineering

Two distinct two-dimensional theories for the modeling of thin elastic bodies are developed. These are demonstrated through numerical simulation of various types of membrane deformation. The work includes a continuum thermomechanics-based theory for wrinkled thin films. The theory takes into account single-layer sheets as well as composite membranes made of multiple lamina. The resulting model is applied to the study of entropic elastic elastomers as well as Mylar/aluminum composite films. The latter has direct application in the area of solar sails. Several equilibrium deformations are illustrated numerically by applying the theory of dynamic relaxation to a finite difference discretization based …

Santa Clara Magazine, Volume 50 Number 2, Fall 2008, Santa Clara University

Santa Clara Magazine

10 - MEET MOUNTAIN By Lisa Taggart. A Q&A with SCU women's basketball coach Jennifer Mountain.

12 - KATRINA AT THREE By Pat Semansky '06. A New Orleans photo essay.

16 - THE MEDDLING PRIEST FROM OZ By Emily Elrod '05. An interview with Australian Jesuit John Brennan, S.J.-lauded as a "national treasure" and an "ethical burr."

18 - 20/20 VISION By Robert M. Senkewicz. How has the presidency of Paul Locatelli, S.J., transformed the University-as a place-and as an idea?

28 - GO WITH YOUR HEART By Francisco Jimenez. An exclusive excerpt from his new memoir, Reaching Out.

32 …

Improved Contact For Thermal And Electrical Transport In Carbon Nanofiber Interconnects, Tsutomu Saito, Toshishige Yamada, Drazen Fabris, Hirohiko Kitsuki, Patrick Wilhite, Makoto Suzuki, Cary Y. Yang

Electrical and Computer Engineering

We study the performance and reliability of carbon nanofiber (CNF) interconnects under high-current stress by examining CNF breakdown for four test configurations, suspended/supported with/without tungsten deposition. The use of W is to improve the CNF-electrode contact. The supported cases show a larger current density just before breakdown than the suspended ones, suggesting an effective heat dissipation to the substrate. The W-deposited contacts reduce the initial total resistance from megaohm range without W to kilo-ohms. High-current stress does not change the total resistance of the test structures with W unlike those without W deposition.

Impact Of Climate Change On Irrigation Water Availability, Crop Water Requirements And Soil Salinity In The Sjv, Ca, Jan Hopmans, Edwin P. Maurer

Civil, Environmental and Sustainable Engineering

We examine potential regional-scale impacts of global climate change on sustainability of irrigated agriculture, focusing on the western San Joaquin Valley in California. We consider potential changes in irrigation water demand and supply, and quantify impacts on cropping patterns, groundwater pumping, groundwater levels, soil salinity, and crop yields. Our analysis is based on archived output from General Circulation Model (GCM) climate projections through 2100, which are downscaled here to the scale of the study area (~30 km across). We account for uncertainty in GCM climate projections by considering output from two different GCM's, each using three greenhouse gas emission scenarios. …

Santa Clara Magazine, Volume 50 Number 1, Summer 2008, Santa Clara University

Santa Clara Magazine

10 - SPEED RACERS An interview by Gwen Knapp. Cycling legend Greg LeMond talks ethics and doping in sports.

14 - MEET THE NEW FATHER GENERAL By Steven Boyd Saum. Introducing Adolfo Nicols, S.J., the new Superior General of the Society of Jesus.

16 - NO SIMPLE HIGHWAY By Juan Velasco. The Casa de la Solidaridad is less a place than a journey—one that offers a new understanding of solidarity. And a new meaning of home.

22 - EXILES By Ron Hansen. A tale of a shipwreck, a priest, and a poet. Hansen tells the story behind his new novel, …

Length Dependence Of Current-Induced Breakdown In Carbon Nanofiber Interconnects, Hirohiko Kitsuki, Toshishige Yamada, Drazen Fabris, John R. Jameson, Patrick Wilhite, Makoto Suzuki, Cary Y. Yang

Electrical and Computer Engineering

Current-induced breakdown is investigated for carbon nanofibers (CNF) for potential interconnect applications. The measured maximum current density in the suspended CNF is inversely proportional to the nanofiber length and is independent of diameter. This relationship can be described with a heat transport model that takes into account Joule heating and heat diffusion along the CNF, assuming that breakdown occurs when and where the temperature reaches a threshold or critical value.

Santa Clara Magazine, Volume 49 Number 4, Spring 2008, Santa Clara University

Santa Clara Magazine

14 - LET THE SUN SHINE IN By Steven Boyd Saum. In the international Solar Decathlon competition, a team from Santa Clara blazed a dazzling trail from almost-ran to third in the world.

20 - VISIONS FROM THE SIXTIES By Lisa Taggart. It was art that broke all the rules. And now an exhibit at the de Saisset Museum, curated by Santa Clara scholar Andrea Pappas, captures the sense of optimism and energy when the only limits were imagination itself.

26 - JORMA'S JOURNEY By Mark Purdy. With Jefferson Airplane, he helped define the San Francisco sound. With Hot Tuna …

Utility Of Daily Vs. Monthly Large-Scale Climate Data: An Intercomparison Of Two Statistical Downscaling Methods, Edwin P. Maurer, Hugo G. Hidalgo

Civil, Environmental and Sustainable Engineering

Downscaling of climate model data is essential to local and regional impact analysis. We compare two methods of statistical downscaling to produce continuous, gridded time series of precipitation and surface air temperature at a 1/8-degree (approximately 140 km2 per grid cell) resolution over the western U.S. We use NCEP/NCAR Reanalysis data from 1950–1999 as a surrogate General Circulation Model (GCM). The two methods included are constructed analogues (CA) and a bias correction and spatial downscaling (BCSD), both of which have been shown to be skillful in different settings, and BCSD has been used extensively in hydrologic impact analysis. Both methods …

Climate Change Scenarios For The California Region, Daniel R. Cayan, Edwin P. Maurer, Michael D. Dettinger, Mary Tyree, Katharine Hayhoe

Civil, Environmental and Sustainable Engineering

To investigate possible future climate changes in California, a set of climate change model simulations was selected and evaluated. From the IPCC Fourth Assessment, simulations of twenty-first century climates under a B1 (low emissions) and an A2 (a medium-high emissions) emissions scenarios were evaluated, along with occasional comparisons to the A1fi (high emissions) scenario. The climate models whose simulations were the focus of the present study were from the Parallel Climate Model (PCM1) from NCAR and DOE, and the NOAA Geophysical Fluid Dynamics Laboratory CM2.1 model (GFDL). These emission scenarios and attendant climate simulations are not “predictions,” but rather are …

Santa Clara Magazine, Volume 50 Number 3, Winter 2008, Santa Clara University

Santa Clara Magazine

12 - ONE GOLD...AND A HOST OF MEMORIES By Ann Killion. A Beijing Olympic scrapbook.

16 - GOD AND WOMAN AT YALE By Steven Boyd Saum. For more than 300 years, the role of Yale University’s chaplain has never been filled by a woman, a layperson, or a Catholic—until now. Meet Sharon M. K. Kugler ’81.

20 - WITH RENEWED VIGOR AND ZEAL By Michael G. Boughton, S.J. How six decrees define the mission of the Society of Jesus in the years to come.

22 - LIBERTY AND THE PURSUIT By Michael S. Malone ’75, MBA ’77. Without meaning to, …