Ultratrace element analysis using synchrotron radiation total reflection x-ray fluorescence
- SLAC/SSRL, Stanford, CA (United States); and others
Trace impurity analysis is essential for the development of competitive silicon circuit technologies. Current best methods for chemically identifying and quantifying surface and near surface impurities include grazing incidence x-ray fluorescence techniques using rotating anode x-ray sources. To date, this method falls short of what is needed for future process generations. However, lie work described here demonstrates that with the use of synchrotron radiation, Total Reflection X-ray Fluorescence (TXRF) methods can be extended to meet projected needs of the silicon circuit industry through at least the remainder of this century. The present results represent over an order of magnitude improvement in detection limit over what has been reported previously. Our best results were obtained using a double multilayer monochromator on the BL10, 32 pole wiggler at SSRL resulting in a detection limit for Ni of 3 x 108 atoms/cm{sup 2}. This is to be compared with a detection limit of 5 x 109 atoms/cm{sup 2} obtained with a rotating anode system. This data was from a sample intentionally contaminated with 1011 atoms/cm{sup 2} Fe, Ni, and Zn. Furthermore, there is a clear path to improving the synchrotron case to reach a detection limit of 5 x 107 atoms/cm{sup 2}. In addition, the tunability of synchrotron radiation makes it possible to achieve this sensitivity for nearly all the atoms in the periodic table. Although these applications have primarily been for silicon integrated circuits, it is clear that these techniques can be more generally applied to the detection of trace elements in a variety of applications of interest to analytical chemistry.
- OSTI ID:
- 466499
- Report Number(s):
- CONF-951017-; TRN: 96:005999-0031
- Resource Relation:
- Conference: 22. annual conference of the Federation of Analytical Chemistry and Spectroscopy Societies, Cincinnati, OH (United States), 15-20 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of FACSS XXII - the 22nd annual conference of the Federation of Analytical Chemistry and Spectroscopy Societies; PB: 285 p.
- Country of Publication:
- United States
- Language:
- English
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