Acquisition of a Dynamic Secondary Ion Mass Spectrometer for Materials Research

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9703930 Kramer This award provides support for the acquisition of a dynamic secondary ion mass spectrometer (SIMS) based on a quadrupole mass analyzer for materials research. It will be installed in the Electron Microscope and Microanalytical Facility of the University of California Santa Barbara (UCSB) Materials Research Science and Engineering Center (MRSEC) and will be open to use by all qualified users at UCSB and the nationwide MRSEC system. The instrument selected is optimized for depth profiling insulating samples such as polymers and ceramics but will also serve the most of the depth profiling needs for semiconductors. It is equipped with a rotation attachment, for improving depth resolution at interfaces well below the surface, as well as a liquid nitrogen cooled sample stage accessory, which will make it possible to depth profile polymers that are molten at room temperature. In addition to the standard duoplasmatron ion source (for oxygen or argon ions), a cesium ion source will be acquired. While an O2+ or AR+ beam is ideal for polymer depth profiling, a Cs+ beam is optimum for depth profiling many elements in semiconductors. The acquisition of this instrument will provide important new capabilities for investigating phase separation in polymer thin films, short range diffusion in ordered block copolymer systems, the grafting of polymer chains to polymer/polymer interfaces by chemical reaction, the structure of surfaces of semifluorinated side group block copolymer surfaces that resist reconstruction in water and of antifouling coatings made of copolymer consisting of water soluble blocks and non-water soluble glassy blocks and for monitoring the formation of molecular bridges between surfaces in hot melt adhesives. %%% While this instrument will have an exceptional impact on research on polymer surfaces and interfaces, it will also be of great value to researchers investigating impurity levels in epitaxial thin films of oxides and diffusion i n ceramics. Moreover the dynamic SIMS will enable much improved characterization of nitrides grown by both metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), as well as multiple quantum well structures in these systems for optoelectronic devices. SIMS depth profiling of Mn in Mn ion implanted GaAs magnetic semiconductors will provide crucial information on the nanostructure of these exciting materials. SIMS determinations will provide key information on vertical cavity semiconductor laser structure grown by MBE, on non-stoichiometry in compound semiconductor layers and on oxide distribution in AlAs layers. In addition the dynamic SIMS capability will provide fundamental understanding of the non-equilibrium diffusion, trapping, and activation of impurities during silicon processing. The high interest shown in this instrument by materials researchers at UCSB and elsewhere is a strong indication that it will be fully utilized to do exciting materials science. ***