CAMP Annual Report:Page 5
Carbon Dioxide Sequestration in Geological Reservoirs-Assessment of Leakage due to the Presence of Abandoned Wells
Professor Ahmadi in collaboration with the scientists from the US Department of Energy is working to assess the safety of carbon dioxide sequestration in geological formation. In particular, the potential for leakage due to the presence of abandoned wells is being studied. As part of this project, computer models for gas-liquid flows in porous media as well as in rock fractures are being developed.
Professor Ahmadi and his student Kevin Shanely (EPA Star Fellow) are studying particle and fiber deposition in the nose for an EPA funded project. They have developed computer models for analyzing airflow in the nasal cavity and for simulating transport and deposition of particles and fibers in the airways.
COLLOIDAL DISPERSIONS AND PROCESSING
Novel Polymers for Photovoltaic Biomedical Applications
Professor Devon Shipp and his team have two focus areas of research: new nanomaterials for photovoltaic (PV) devices and novel degradable elastomers. The PV research, which leverages their expertise in polymer synthesis and nanocomposites, aims to create low-cost, large-area PV devices through the use of phase separation in block copolymers leading to well-ordered polymer nanocomposites. Such hybrid nanomaterials have great potential for applications in photo- and electrochemical devices (e.g. solar cells, sensors). The work in Professor Shipp's laboratory is funded by NYSERDA and the US Army Research Office. In the second area of research, on degradable elastomeric polymers, Shipp and his students have demonstrated that linear and crosslinked polyanhydrides can be made using photoinitiated thiol-ene chemistry. This is a simple and effective method of making crosslinked structures that have surface degradation characteristics. See Figure 1. A paper describing this work will soon appear in Chemical Communications. This technology may be expected to gain usage in many biomedical applications such as drug delivery, orthopedics, tissue engineering and scaffolds. More information about Professor Shipp's research activities can be found at www.clarkson.edu/~shippda.
Figure 1. Work in Professor Devon Shipp's laboratories has shown that photoinitiated thiol-ene chemistry is a simple and effective method of making crosslinked structures that have surface degradation characteristics.
Cu/Barrier and Dielectric Film Polishing and Planarization
Professor S.V. Babu's research group is continuing its fundamental investigations of various aspects of chemical-mechanical planarization (CMP) of metal and dielectric films focused on developing slurry formulations that are more active chemically for low pressure planarization of Cu, while ensuring appropriate selectivity with respect to the underlying barrier and low-k dielectric films. While hydrogen peroxide is likely to remain the primary oxidizer in such slurries due to its multiple advantages, several compositions involving glycine or carboxylic acids (oxalic, acetic, citric, malonic, succinic, glutaric, etc.) and, in some cases, their mixtures as complexing/chelating agents appear to be very interesting. For example, single dispersion candidate slurries for polishing both Cu and the barrier layer using oxalic and tartaric acid as complexing agents have been proposed and the results have been already published. The necessary selectivity between Cu and the Ta barrier layer can be achieved by just modifying the pH. Evaluation of these dispersions using 300 mm pattern wafers has been completed with very good results. Also, two surfactants - ammonium dodecyl sulfate and dodecyl benzene sulfate - that can suppress the Cu dissolution rate and help to achieve high planarization efficiencies for Cu CMP have been identified. In some cases, a small amount of BTA significantly enhanced this protective ability by forming a very compact passive film on the Cu surface, while in others, there is no need for BTA. In the absence of BTA, these reagents also help to minimize defects and facilitate post-CMP cleaning.
Also, investigation of controlled selectivity in material removal when oxide, nitride and/or poly-Si films are being polished has led to several attractive candidate slurries. Several ceria and silica based compositions that yield a high nitride and low oxide polish rate and simultaneously a controllable poly-Si removal rate have been identified. Several new patents and disclosures have been filed. Defect characterization and mitigation studies using a variety of hard core/soft shell type composite abrasives also remain of great interest.
Professor S.V. Babu Reappointed ...
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Babu has delivered plenary and keynote lectures at numerous international and national conferences on CMP and has organized the internationally renowned annual symposium on CMP in Lake Placid for the last 14 years, as well as many CAMP conferences and symposia. More recently, he has been leading CAMP's research efforts in the area of advanced materials for photovoltaic devices and systems as well as energy storage.
An outstanding scientist in his own right, Babu has published more than 200 papers in journals and conference proceedings, edited three books on CMP, and has co-authored more than 25 patents, some of which were licensed and have already generated over $400,000 in royalties to Clarkson. Under Babu's mentorship, 31 doctor of philosophy and 35 master of science students have completed their degrees. Many undergraduate students have also worked in his research group.
Some of Babu's current research interests include CMP of Cu, Ta, and low-k and other dielectric films for metallization and shallow-trench isolation in semiconductor device fabrication, and thin film processing for photovoltaic applications. His own research, which has generated around $8 million in funding, has been supported over the years by the National Science Foundation, the U.S. Department of Defense, IBM, Intel/SRC, Kodak, Ferro Electronics, Infotonics Technology Center, Ebara, St. Gobain, Umicore, Rhodia, BASF, NYACOL Nano Technologies, Climax Engineered Materials, NYSERDA, PPG Industries, and Rohm & Hass, among others. He is also a consultant with several companies in the area of CMP and thin films.
Babu joined Clarkson in 1981 as an associate professor of chemical engineering and served as the vice provost for research during 2001-2004. He completed his doctorate at SUNY Stony Brook in physics after graduate study in chemical engineering at Johns Hopkins University. He was at the Niels Bohr Institute in Copenhagen and for eight years on the faculty at IIT, Kanpur, before coming to Clarkson. He has also worked with IBM at Endicott, Bellcore and Sandia National Laboratories while on leave from Clarkson.
The Center for Advanced Materials Processing at Clarkson University is dedicated to developing Clarkson's research and educational programs in high-technology materials processing and is focused on finding solutions for technical challenges faced by industrial concerns. CAMP's mandate is to develop innovations in advanced materials processing and to transfer this technology to business and industry.
The Center's core technologies are rooted in Clarkson's recognized expertise in colloid and surface science and fine particle technology. CAMP receives support from NYSTAR for research and operating expenses as one of 15 Centers for Advanced Technology (CATs). In addition, CAMP-related work receives several million dollars each year from the federal government and private industry.