Project 1. Electrical and Optical Characterization of Phase Change Materials
Simone Raoux (simone_raoux@almaden.ibm.com)
Phase change materials exist in two different phases (amorphous and crystalline) that have very different optical and electrical properties. They are applied in re-writable CD's and DVDs to store the information by having amorphous bits in a crystalline matrix. The information is read by measuring the reflectivity that differs between the two phases. We want to develop solid state memory devices that apply phase change materials and use their very different resistivity to store the information.
The summer intern will learn how to deposit phase change materials using a state-of-the-art sputter deposition tool. The project will include the deposition of novel phase change materials and their characterization. The characterization will include measuring the resistivity as a function of temperature and determining the crystallization temperature. It will further include the testing of the crystallization speed and optical materials properties applying a laser set-up. The intern will perform mostly work in the laboratory and some analysis of the experimental data. Laboratory experience is a plus, but enthusiasm is most important.
http://www.almaden.ibm.com/st/nanoscale_st/nano_devices/phasechangememory
Project 2. Organic Catalysis: A General Platform for Living Polymerization
Jim Hedrick (hedrick@almaden.ibm.com)
Technological advances continue to present many complex ecological issues. As a consequence, pollution prevention and waste management constitute two significant challenges of the 21st century. Since the recent establishment of a green program at the EPA, modern synthetic methodologies are encouraged to preserve efficacy of function while minimizing toxicity, use renewable feedstocks, and use catalytic and /or recyclable reagents to minimize waste. Growing trends in asymmetric synthesis for classic reactions that use organic molecules as promoters have provided an alternative to traditional organometallic reagents. We have developed a series of new organic catalyst platforms for living polymerization. The development of these new catalysts has led to novel patterns of reactivity for the enchainment of monomers to structurally well defined macromolecules. In this summer program, we will continue this general strategy to well-defined macromolecules by exploiting the unique mechanistic aspects of organic catalysis.
http://www.almaden.ibm.com/st/chemistry/ps/catalysts/
Project 3. Spin-on Thin Films for Advanced Memory Applications
Delia Milliron (milliron@us.ibm.com)
The search is on for a new memory technology that will be faster, cheaper, and more scalable than Flash. Two leading candidates - phase change memory and resistive switching memory - rely on the properties of metal chalcogenide materials. Projects are underway at IBM Almaden to better understand what makes these new memory materials work and to discover improved compositions to enable upcoming memory technology. This project involves the unconventional deposition of metal chalcogenide films from solution, using the spin coating processes commonly used for photoresists and other polymers. This low cost, low tech approach has recently emerged as an alternative method to deposit electronic materials for devices ranging from transistors to memory to solar cells. Previous interns at Almaden have helped advance the start of the art in spin-on phase change materials. This year's intern will contribute to the development of improved phase change and resistive memory materials using spin-coating. The intern will apply basic chemistry lab and basic processing techniques and learn to work with air-sensitive materials. Materials and device characterization techniques will be learned and applied as needed for this project.
Reference:
DJ Milliron,
Project 4. Nanocrystal Films for Cost-effective Solar Cells
Delia Milliron (milliron@us.ibm.com)
The need for clean, renewable energy to make a meaningful contribution to the world’s energy supply has never been more apparent. For photovoltaic solar power to have a large scale and long term impact, the cost of solar panels must be reduced without sacrificing much in the way of performance. Semiconductor nanocrystals, which are synthesized and processed at low temperature and in solution, offer a potential solution. Their optical properties have been demonstrated to be better even than thin film or crystalline silicon solar cell materials and the challenge is now to integrate them into films and into photovoltaic devices. IBM Almaden has an on-going project to develop the synthesis of new nanocrystals for solar cells and to integrate them into solar cell structures. This summer’s intern will explore conditions for the deposition of nanocrystal thin films from solution and apply spectroscopy to characterize the resulting optical properties. Along the way, the intern will become acquainted with the synthesis and characterization of these advanced materials.
Project 5. Nanoparticle Synthesis, Characterization and Controlled Placement
Sally Swanson (saswans@almaden.ibm.com)
The miniaturization of electronic circuits to the micrometer size scale has been a key driving force for the scientific and economic progress in microcomputers. The extension of this trend into the nanometer-size range suggests the use of nanoparticles as building blocks for nano-sized circuits. The self-assembly and organization of nanoparticles into well defined architectures or desired structures may be a key step in the bottom-up approach toward nanomaterial development. Nanoparticles have also been actively pursued for many other potential uses in technology. This project will involve the synthesis and characterization of nanoparticles, their stabilization in organic solvents, and the manipulation and controlled placement for use in nanotechnology.
Project 6. Nanoparticles for Magnetic Recording
Pierre-Olivier Jubert (pjubert@almaden.ibm.com)
Projects are underway at the Almaden Research Center to investigate future media for magnetic recording, and particularly for archival storage on magnetic tape [1]. The focus is on new, small magnetic nanoparticles, about 10-20nm in size, which would combine small size distribution, be thermally stable and present reasonable coercivity. The team at Almaden has been investigating the synthesis of promising cobalt ferrite (CoFe2O4) nanoparticles. The project proposed here aims at improving the properties of the nanoparticles by incorporating for instance rare-earth elements (such as Nd, Gd). The summer intern will chemically synthesize the nanoparticles, and characterize both their structural properties (using scaning electron microscopy, X-ray diffraction) and magnetic properties (using vibrating sample magnetometer). Ultimately, these nanoparticles also have to be incorporated in polymer / or deposited by self-assembly to form the magnetic media.
[1] Links to tape research webpages:
http://www.almaden.ibm.com/st/magnetism/magnetic_storage/tape/
http://www.almaden.ibm.com/st/magnetism/magnetic_storage/tape/ATL/
Project 7. Advanced Patterning Materials and Processes
Daniel P. Sanders (dsand@us.ibm.com)
Optical lithography has enabled the semiconductor industry to follow the torrid pace of Moore's law over the last 30 years. Advancements in lithographic materials has been a key enabler of the industry as it broke through the 1 micron barrier thanks to revolutionary patterning materials developed here at IBM Almaden. Despite manufacturing nanoelectronic devices for many years now, another inflection point is approaching as advanced research is focusing on patterning features with dimensions at or below 32 nm. In this size regime, the champion patterning technology is far from clear as the industry waits for the struggling extreme ultraviolet lithography (EUV) technology to be ready for high volume manufacturing. Fortunately for researchers like us, this uncertainty has inspired a wide ranging search for alternative patterning materials and processes. Our research group is focused on extending conventional patterning technologies beyond their expected limits and exploring ways in which non-traditional patterning processes such as "bottom-up" approaches like those based on self-assembling diblock copolymers can be turned into manufacturable processes.
This summer project may involve varying amounts of synthesis of polymeric patterning materials and characterization of their imaging performance with Almaden's deep-UV (248 nm and 193 nm) projection and 193 nm immersion interference exposure tools. Particular interest will be paid to double patterning processes in which the new patterning material/process (such as a new photoresist or a self-assembling diblock copolymer) is used in conjunction with an already patterned structure (generally, a patterned conventional photoresist or chemically patterned surface), thereby enabling patterns to be formed with dimensions/densities which are impossible to create with one imaging layer alone.
Research in our group is highly multi-disciplinary, ranging from organic/polymer synthesis to analytical materials science to lithographic patterning and processing. Depending upon the interests and background of the student, the project can be tailored from anywhere from purely synthetic to purely imaging and characterization to anywhere in between.
Here are a few useful links about our group and the field of lithography:
http://www.almaden.ibm.com/st/chemistry/lithography/index.shtml
http://www-03.ibm.com/chips/about/technology/makechip/index.html
http://en.wikipedia.org/wiki/Photolithography
http://en.wikipedia.org/wiki/Immersion_lithography
Supramolecular Materials for Microelectronics Applications
Alshakim Nelson (alshak@us.ibm.com)
As the current trend of creating smaller electronic devices continues, there is an increasing need to develop the materials and processes required to continue this trend. Emulating the assembly processes as they occur in Nature is one route to generating new materials for microelectronic devices that require particular attention to events as they occur at the nanoscale. We focus on using and understanding molecular recognition to control the self assembly of polymeric materials on surfaces. This includes employing controlled polymerization techniques to incorporate molecular functionalities into macromolecular architectures to control the manner by which they assemble
Project 9. Directed Self-assembly for Resolution Enhancement Non-equilibrium State
Joy Cheng (chengjo@us.ibm.com)
Optical lithography has been the work force of patterning semiconductor devices of ever shrinking critical dimension (CD). Smaller CD allows denser circuitry to be created and therefore reduces overall production cost. Over 30 years, optical lithography has kept scaling down to 45 nm half-pitch by reducing source wavelength, introducing new tools and materials as well as optimizing exposure and mask design. However, the resolution limits of the state-of-art optical lithography make patterning at 32nm half-pitch and beyond a challenge. Directed self-assembly, where polymer self-assembly is guided by the lithographically defined features, provides an alternative approach to enhance the resolution of optical lithography with simple and low-cost process. This summer project will involve experimental works on optical lithography, polymer self-assembly and nanostructure characterization.
References:
Directed self-assembly for extending optical lithography: http://www.future-fab.com/documents.asp?grID=213&d_ID=3022
Directed self-assembly for advanced patterning: http://www.almaden.ibm.com/st/chemistry/ps/self_assembly/block_copolymer/placement/
Project 10. Improving TEM Sample Preparation of Magnetic Multilayer Specimens
Philip Rice (pmrice@almaden.ibm.com)
Leslie E. Krupp (lkrupp@us.ibm.com)
Magnetic multilayers are important in research on magnetic random access memory and magnetic sensors and have many applications in other technologies. TEM is vital for characterization of these films. The effect of the sample preparation method on the structure or surface of a sample (usually less than 40 nm thick) is a perennial question. In this project the intern will conduct mechanical polishing and ion milling experiments to find the best conditions for consistently producing damage free TEM cross sections from magnetic multilayers on Si coupons. The intern will learn to use the state-of-the-art Multiprep TM polishing system, the precision ion polishing system (PIPSTM), and a "Gentle Mill" (200 volt) ion polisher at IBM. These sample preparation methods are essential for the subsequent use of Field Emission TEM studies on a JEOL 2010F. A comparison of the effect of the preparation methods will come from TEM and EELS results on the samples. If the modifications to the 'Gentle Mill' ion polisher are complete, the intern will help calibrate the instrument as well as develop and write a standard operating procedure (SOP) for the newly configured ion mill.
Project 11. Placement Control of Nanostructures from Self-assembly of Block Copolymers
Ho-Cheol Kim (hckim@almaden.ibm.com)
Block copolymers, consisting of two or more distinct homopolymers joined end to end, self-assemble into periodic microdomains with typical dimension of 10 – 50 nm. Patterning with thin films of block copolymers are of particular interest to the semiconductor industry, where the evolution of silicon-based devices is governed by the ability to create ever shrinking dimensions of patterns. However, many challenges remain to be met in order to use block copolymers as a viable patterning material, including the need to better understand and control defects, to obtain large area order, and to minimize variations in microdomains dimension, edge roughness, and lateral placement. This project will focus on processes for fabrication of spatially controlled nanostructures of block copolymers on substrates. The effect of sub-micron scale spatial confinement and surface interaction on the self-assembly of block copolymers in thin film geometry will be investigated using both lamellar and cylindrical microdomains of block copolymers
Project 12. Directed Assembly of Nanoparticles and Nanorod on DNA Scaffolds
Jennifer Cha (chaj@us.ibm.com)
Due to Nature's ability for self-recognition and assembly, a significant amount of research has focused at using biological systems to assemble nanoscale materials, such as nanoparticles, nanowires and carbon nanotubes. Recently, DNA based templates have garnered enormous interest due to their use as potential genetic "blueprints" for the directed placement of nanoscale materials. Currently we are developing methods to both direct the placement of individual DNA scaffolds on lithographically patterened substrates as well as use the DNA scaffolds to organize sub-10nm materials, such as metal or oxide nanoparticles. The focus of this particular project will be to investigate different chemical and biochemical approaches to attaching single strands of DNA to nanoparticles and nanowires. The summer research intern will learn collodial synthesis of metal and oxide nanoparticles, functionalization of nanoparticles and nanowires, bioconjugation and characterization.
Project 13. The Creation and Control of Organic Structures on the Submicron Scale
Jane Frommer (frommer@almaden.ibm.com)
Structures of less than one micron in dimension now appear frequently in research labs and in product applications, yet at this scale the limited population of molecules in an inhomogeneous surroundings can result in unpredictable properties. We study the behavior and control of organic interfaces as they are limited to submicron feature sizes. Lithographic and surface derivatization techniques are used to create small structures, and atomic force microscopy and other surface analytical techniques are used to probe the localized features and their properties. Due to the interdisciplinary nature of the study of nanostructures, we collaborate with biologists and synthetic chemists to customize surfaces and materials.
Project 14. Self-Organizing Bioinspired Organic Photovoltaics
Robert Miller (rdmiller@almaden.ibm.com)
The total amount of solar energy available at the Earth’s surface is greater than the current energy needs for the whole of mankind. The efficiency with which Natural photosynthetic structures make use of this abundant energy resource makes them obvious targets for synthetic emulation. Of particular interest for study are the underlying mechanisms by which photonic energy is efficiently converted into electronic potential by self-assembled organic molecules. Inspired by these Natural design elements, the creation of artificial “light-harvesting” systems is currently the subject of intense world-wide investigation. The lessons learned from the interrogation of such synthetic systems have far reaching implications for a wide range of topical applied research areas ranging from organic-based molecular electronics to nanoscale switching and sensor devices to quantum-dot technologies to bio-photonic medical applications.
Project 15. The Design of Lanthanide-Based Luminescent Probes
Gilles Muller(gmuller@science.sjsu.edu)
Rick DiPietro(dipietro@almaden.ibm.com)
The design of new medical drugs and therapies rely on chiral recognition, a tool that determines which of the two isomers is present in the solution and to assure that we only have the active species in lieu of the inactive/ toxic one. This project will focus on the design, synthesis and characterization of luminescent lanthanide complexes prior to using them as probes in selective recognition of chiral amino acids using a unique type of spectroscopy, namely circularly polarized luminescence (CPL). In order to be useful, these compounds need to be designed with improved stability, efficiency and, in particular, selectivity. Accordingly, choosing selected (i) sensitizing and (ii) discriminating moieties into the lanthanide(III) complex molecules will achieve it.
The intern will synthesize and characterize the ligand prior to determining its structural and photophysical properties using NMR, FTIR, UV-Vis, and luminescence spectroscopic experiments. Interaction between the ligand and Ln(III) ions will be envisaged using various spectroscopic techniques for gaining information about the stability of the system of interest. Information concerning metal ion-ligand environments and associated chiral structure of these systems can be obtained through the measurement of circularly polarized luminescence (CPL).
Project 16. Atomic Force Microscopy Studies of Chemically Modified Capillaries
Jane Frommer (frommer@almaden.ibm.com)
Joe Pesek (pesek@sjsu.edu)
This project involves characterizing the inner surfaces for capillaries that have been etched and chemically modified by bonding various organic compounds. A number of different techniques can be used. Scanning electron microscopy (SEM) provides a good visual indication of the topography of the etched surface Atomic force microscopy (AFM) provides a better understanding of surface topography as a function of derivatizing conditions and the nature of the bonded groups. The intern will learn these methods of characterization and techniques for attaching various compounds to AFM tips for the measuring surface properties. Since the tips are made of silicon, bonding reactions designed for surface oxide layers can be used. This approach has been tested and preliminary images correlate well to the images produced by a conventional AFM tip. Force measurements have also been made between these tips and the inner walls of etched chemically modified capillaries. With the modified tips, the intern will measure the specific forces that mimic the types of interactions between various molecules and the bonded group on the wall of the capillary. The intern's AFM measurements will determine the uniformity of surface coverage as well as roughness which, in the past, indicated surface area increases in the range of several hundred to a thousand fold or more. These experiments help identify potential applications for the capillaries and are essential to the fundamental understanding of chemically modified capillaries as an electrophoretic separation medium.
Project 17. Nanoelectromechanical Surfaces
Roger Terrill (rterrill@jupiter.sjsu.edu)
This collaborative project leverages the surface analysis expertise and instrumentation that we have here at SJSU with the nanoparticle preparation and characterization skills of the Shaowei Chen group at U.C. Santa Cruz. In this project we aim to prepare novel electromechanically active surfaces. The intern will modify gold surfaces by the stepwise coupling of a series of molecular linkers and finally nanoparticles.
Project 18. Infrared Spectroscopic Tools for Biosensing
Roger Terrill (rterrill@jupiter.sjsu.edu)
This project aims to combine the highly successful biosensor technology known as surface plasmon resonance spectroscopy (SPR) with the informative spectral response of the infrared wavelength regime. The application of infrared spectroscopy to biosensing promises to add a dimension of information to an already successful technique.