Aquisition of a Dual-Beam Focused Ion Beam System

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This grant supports the acquisition of a dual-beam focused ion beam (FIB) processing system for nanoscience research in advanced materials and in the biosciences at Johns Hopkins University. A FIB system uses a finely focused beam of high-energy ions to selectively remove material from a target with nanometer precision, functioning as a "nano-scale milling machine." A FIB can also perform nanodeposition of materials with feature sizes down to 30 nanometers by local stimulation of gaseous precursors. FIB devices have been used in the semiconductor industry for approximately a decade for post-fabrication repairs, modification, and quality control analysis of integrated circuits. However, these systems also have great utility for basic research, particularly for the fabrication of nanostructures and devices that cannot be made by conventional microlithographic techniques. New research directions that acquisition of the FIB system will enable span a wide range and include (i) the study of new materials and devices for "spintronics," a potential new class of microcircuitry that employs spin currents as well as conventional electrical currents to carry and store information; (ii) the development of new stencil mask methods of nanostructure fabrication; (iii) studies of electronic transport properties of macromolecules; (iv) fabrication of high performance cantilevers for atomic force and magnetic force microscopy, with particular potential for applications in the biosciences; (v) fundamental studies of the mechanisms of cell adhesion and growth on nanoengineered surfaces, with relevance for tissue engineering; (vi) fundamental studies of the dynamics of materials' surfaces; and (vii) site-specific sample preparation for high-resolution transmission electron microscopy studies of nanostructured devices, geological materials, and biomineralization. In addition to the primary ion beam, the dual beam instrument will have an electron beam for high-resolution scanning electron microscopy of samples in the FIB chamber. This will allow non-destructive imaging and analysis of sensitive nanoscale features produced by the FIB. The system will also be equipped for nanodeposition, automated TEM sample preparation, and in-situ electrical measurements for fabrication analysis and measurements of the properties of nanoscale devices. The new FIB instrument will greatly enhance the research training of several postdoctoral fellows and twenty graduate students involved in the research. As the instrument will be made available to the broader Johns Hopkins research community, its impact on research training is expected to grow with time. The instrument will be integrated into undergraduate courses, and into the extensive Education Outreach Programs focusing on materials research that are already in place at Johns Hopkins for high school students, high school teachers, and undergraduates. All of these programs have had considerable success in reaching traditionally underrepresented groups, and the increased opportunity to use state-of-the art instrumentation that this FIB system will provide will further these programs' goals of developing a more diverse and talented scientific workforce.