This Small Business Innovation Research (SBIR) Phase I project will investigate the use of polycapillary optics for the determination of low atomic number (Z) elements (Z<14) on silicon (Si) semiconductor substrates using X-ray fluorescence (XRF). Light element contamination is a significant problem in semiconductor production resulting in reduced device yields, increased production costs, and impaired industrial competitiveness. No satisfactory analytical technique is available that is both nondestructive and has the necessary detection limits as set by the Semiconductor Industry Association (SIA) National Technology Road Map for Semiconductors (NTRMS). It is predicted that the technology of polycapillary X-ray optics can effectively collect a large solid angle of X-rays and preferentially transmit photons below the Si absorption edge. The transmitted beam can be focused upon the targeted area of a Si semiconductor with high intensity. The performance characteristics of several polycapillary fibers will be studied for transmission of low energy X-rays in different geometric configurations. These results will be used to design a novel polycapillary optical system for low energy XRF and improve the signal-to-noise ratio for light element analysis. Applications of the research are expected to extend the capability of the XRF technique to a greater range of light elements and will be particularly useful in the semiconductor industry. These applications will include materials synthesis and processing, electronic and photonic device fabrication, and microfabrication. Improved semiconductor device yields and more competitive analytical instrumentation are expected.
