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| Home : Faculty : | |
| Richard J. Matyi |
| Richard J. Matyi Professor
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| Primary Address:
242 Materials Science And Engineering Building 1509 University Avenue Madison, WI 53706 Tel: 608/263-1716 Fax: 608/262-8353 E-mail: richard.matyi@nist.gov |
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Secondary Address:
Atomic Physics Division, NIST
100 Bureau Drive, Stop 8422 Gaithersburg, MD 20899 Tel: 301/975-4272 Fax: 301/975-3038 |
X-ray diffraction is one of the most powerful analytical methods for providing information regarding the structural properties of materials. We are particularly interested in the development and application of very high resolution diffraction techniques to the analysis of bulk and thin film semiconductors. For instance, we are using X-ray diffraction methods for the quantitative characterization of growth defects in II-VI semiconductors such as CdTe, CdyZn1-yTe, and CdTezSe1-z. We are also using high resolution X-ray diffraction methods to develop an improved understanding of the mechanism of material removal and defect generation in chemical-mechanical polishing and reactive ion etching.
In contrast with semiconductor crystal growth, the growth of high quality protein crystals is much more difficult. Reproducibility is a problem, and "large" single crystals are typically less than 1mm3. Most importantly, the structural quality of protein crystals is considerably lower than modern semiconductor materials. X-rays are used extensively by protein crystallographers, but usually only for structural determination; however, the accuracy of these structural analyses is adversely affected by the large number of defects in protein crystals. We are therefore applying techniques of high-resolution X-ray diffraction to the analysis of protein crystals. Ultimately, these analyses are expected to lead to a better understanding of the conditions that limit structural quality in protein crystal growth. Characterization of grown-in defects could lead to methods of reducing their densities, thereby increasing crystalline quality and improving the structural determinations that are central to the study of protein function.
The ability to fabricate single crystal materials on a non-crystalline substrate would be a significant advance in both the science and technology of semiconductor materials and would impact all phases of electronic and photonic applications. We are exploring a novel approach - the photo-assisted deposition of materials using X-ray standing waves - as a method for achieving this heretofore unattainable goal. Our approach relies on the generation of a two-dimensional X-ray standing wavefield (XSW) to form a nucleation layer on a model substrate system (SiO2/Si). This research program is performing proof-of-concept experiments in a laboratory using a rotating anode X-ray generator and flux-enhancing optics to demonstrate XSW-assisted, ordered deposition, in preparation for migration to a synchrotron source to demonstrate successful "XSW-induced" (not epitaxial) growth on non-crystalline "hostile" substrates.
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Copyright 2005 The Board of Regents of the University of Wisconsin System Date last modified: Friday, 19-Oct-2001 13:37:05 CDT Content by: richard.matyi@nist.gov Thank you for visiting! |
