SBIR-STTR Award

Micro-diffraction-based crystallography is essential to materials design and process understanding in key industrial applications such as microelectronics, superconductivity, solar energy, structural composites, and metal forming. The scanning electron microscope (SEM) can provide high spatial resolution crystallographic information, but its applicability is limited by the low sensitivity of existing techniques, The current methodology cannot be easily used for dose-sensitive materials, electrical nonconductors, and samples with even small amounts of surface damage. The difficulty of obtaining microdiffraction data is a drawback in the SEM, which otherwise is useful in obtaining high resolution topographical and compositional information, and usually requires minimal specimen preparation. The project is determining the feasibility of,employing an energy filtering detector with high gain to increase the sensitivity of micro-diffraction in the SEM. The filter is being applied to backscattered electron patterns that provide crystallographic information at very high spatial resolution. The study requires an -amplifying element that is sensitive to low energy electrons, such as a microchannel plate. The research is testing the overall feasibility of this approach as well as the specific issues of dynamic range and noise level. Exploitation of the research would improve the competitive position of domestic industries by enhancing their capability to identify component and define aggregate properties related to advanced materials and processes. In addition, it would extend the functionality of a large existing base of scanning microscopes used in academic and industrial research.The potential commercial application as descri; bed by the awardee: Research will resul4 in the provision of texture analysis systems, micro-diffraction systems, and dark-field detection systems for the SEM.

SBIR Phase-II funds are provided to investigators at Advanced Microscopy Techniques to develop an energy filter for electron backscatting patterns (EBSP) with fine pattern resolution and a large acceptance angel. The Phase-II research objectives are: 1) to develop an energy filter and EBSP sensor element that retains high quality micro-diffraction patterns with improved contract due to energy filtering, and 2) maintain a large acceptance angel for the microdiffraction patterns. If these improvements can be made, two major advances would be possible. First, the visibility of the diffraction pattern would improve for both direct viewing and for digital acquisition and analysis. This would extend EBSP ( and consequently SEM) to a greater variety of applications and materials. Second, the new device could serve a dual purpose as both an EBXP detector and a small angle (dark field) detector. Thus, both quantitative analysis of diffraction patterns and qualitative diffraction imaging are available to the materials researcher. The success of this research will lead to a Phase-III program to develop a system that can be used in basic research, materials design and manufacturing support. The technique can be adapted to both new electron microscopes and the large existing base of SEMs - allowing the fullest use of SEM technology in materials characterization.