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Search Publications by Daniel Wheeler

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Displaying 1 - 25 of 51

PFHub: The Phase-Field Community Hub

April 17, 2019
Daniel Wheeler, Trevor Keller, Jonathan E. Guyer, James A. Warren, Stephen DeWitt, Andrea Jokisaari, Daniel Schwen, Larry Aagesen, Olle Heinonen, Michael Tonks, Peter Voorhees
An online portal provides a valuable space for scientific communities to summarize a shared challenge, collect attempts at a solution, and present a quantitative comparison of past attempts in a compelling way. An exemplar of such a portal is μMAG. The

Microstructure Knowledge Systems for Capturing Process-Structure Evolution Linkages

June 14, 2017
James A. Warren, Daniel Wheeler, David Brough, Surya Kalidindi
This paper develops and demonstrates a novel data science framework for capturing and communicating critical information regarding the evolution of material structure in spatiotemporal multiscale simulations of various processing operations employed by the

Spatial-Temporal Modeling of Extreme Bottom-Up Filling of Through-Silicon-Vias

December 6, 2013
Daniel Wheeler, Thomas P. Moffat, Daniel Josell
Extreme bottom-up superfilling of annular through-silicon-vias (TSV) during copper electrodeposition has been reported wherein metal deposits on the bottom surface of the TSV with negligible deposition on its sidewalls or the field around it. The growth

Modeling Extreme Bottom-Up Filling of Through Silicon Vias

August 29, 2012
Daniel Josell, Daniel Wheeler, Thomas P. Moffat
Extreme bottom-up superfilling of through silicon vias (TSV) was recently described wherein deposition occurs on the bottom surface of the vias with negligible deposition on their sidewalls or the field around them. The process uses a deposition

Predicting Microstructure Development During Casting of Drug Eluting Coatings

September 19, 2010
David M. Saylor, Jonathan E. Guyer, Daniel Wheeler, James A. Warren
We have devised a novel diffuse interface formulation to model the development of chem- ical and physical inhomogeneities, i.e. microstructure, during the process of casting drug eluting coatings. These inhomogeneities, which depend on the coating

Modeling Reactive Wetting when Inertial Effects are Dominant

June 30, 2010
Daniel Wheeler, James A. Warren, William J. Boettinger
Recent experimental studies of molten metal droplets wetting and spreading on high temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper

FiPy: PDEs in Python

February 23, 2009
Jonathan E. Guyer, Daniel Wheeler, James A. Warren
Partial differential equations (PDEs) are ubiquitous to the mathematical description of physical phenomena. They describe the relationships between functions of more than one independent variable and partial derivatives with respect to those variables

Superfilling When Adsorbed Accelerators Are Mobile

February 6, 2007
Daniel Josell, Thomas P. Moffat, Daniel Wheeler
Bottom-up superfill during electrodeposition that is used for industrial processing of damascene copper interconnects has also been demonstrated during electrodeposition of silver and gold. The Curvature Enhanced Accelerator Coverage (CEAC) mechanism has

Curvature Enhanced Adsorbate Coverage Model for Electrodeposition

January 11, 2006
Thomas P. Moffat, Daniel Wheeler, Soo K. Kim, Daniel Josell
The impact of leveling additives acting through the traditional leveling mechanism of accumulation and consumption has been coupled with the Curvature Enhanced Accelerator Coverage (CEAC) mechanism previously used to explain bottom-up superfill of features

Gold Superfill in Sub-Micrometer Trenches: Experiment and Prediction

November 16, 2005
Daniel Josell, Daniel Wheeler, Thomas P. Moffat
Bottom-up deposition of gold in fine trenches, also called superfill, was recently demonstrated using a submonolayer coverage of preadsorbed, deposition-rate-accelerating lead followed by gold electrodeposition. The present study has used experiments on

FiPy: A Finite Volume PDE Solver Using Python

September 1, 2005
Daniel Wheeler, Jonathan E. Guyer, James A. Warren
The solution of coupled sets of partial differential equations (PDEs) is ubiquitous in continuum models for phase transformations, such as in phase field or level et simulations. We are developing an object-oriented PDE solver, written in the Python

Superconformal Deposition and the CEAC Mechanism

February 27, 2004
Thomas P. Moffat, Daniel Wheeler, Daniel Josell
The mechanism and modeling of superconformal film growth used in the electrochemical fabrication of 3-D Cu interconnects is briefly reviewed. The central role of electrolyte additives in controlling feature filling is fully described by the curvature

An Exact, Algebraic Solution for the Incubation Period of Superfill

January 1, 2004
Daniel Josell, Thomas P. Moffat, Daniel Wheeler
Recent publications have used the impact of area change coupled with conservation of adsorbed catalyst to quantify the superfill effect of bottom-up feature filling during electrodeposition and chemical vapor deposition. This work describes how that

Seedless Superfill: Copper Electrodeposition in Trenches with Ruthenium Barriers

August 4, 2003
Daniel Josell, Daniel Wheeler, C Witt, Thomas P. Moffat
Superconformal filling of fine trenches during electrodeposition of copper is described. Copper electrodeposition was accomplished durectly on a ruthenium layer. The ruthenium layer, as well as a titanium layer to promote adhesion, was evaporated on

Influence of a Catalytic Surfactant on Roughness Evolution During Film Growth

July 24, 2003
Daniel Wheeler, Thomas P. Moffat, Geoffrey B. McFadden, Sam R. Coriell, Daniel Josell
celerator Coverage (CEAC) based mechanism for the impact of additives on the evolution of surface roughness is explained; the CEAC mechanism accounts for the conservation of locl coverage of adsorbed catalyst on a deforming interface. It has recently been

Modeling Superconformal Electrodeposition Using the Level Set Method

May 1, 2003
Daniel Wheeler, Daniel Josell, Thomas P. Moffat
Superconformal filling (superfill) occurs when a high aspect ratio feature on a silicon wafer fills due to preferential metal deposition on the bottom surface that permits it to escape before deposition on the side walls causes them to close off. This

Superconformal Silver Deposition using KSeCn Derivatized Substrates

May 1, 2003
B C. Baker, C Witt, Daniel Wheeler, Daniel Josell, Thomas P. Moffat
Superconformal filling of sub-micrometer trenches was achieved using substrates that were catalyzed with KSeCn prior to metal deposition in a catalyst-free, silver-cyanide electrolyte. The degree of superfill was found to be dependent on the time the

Interconnect Fabrication by Superconformal Iodine-Catalyzed Chemical Vapor

April 3, 2003
Daniel Josell, S D. Kim, Daniel Wheeler, Thomas P. Moffat, S G. Pyo
The mechanism behind superconformal filling of fine features during surfactant catalyzed chemical vapor deposition is described and the metrology required to predict it is identified and quantified. The impact of adsorbed iodine coverage on copper

Accelerator Aging Effects During Copper Electrodeposition

April 1, 2003
Thomas P. Moffat, B C. Baker, Daniel Wheeler, Daniel Josell
Slow sweep rate voltammetric analysis of the Cu/Cu(II) deposition reaction is shown to be an effective tool for examining aging effects associated with thiol and disulfide additives that are widely employed as brighteners. Sulfonate-terminated short chain