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A Study of Defects Due to Surface Processing in Silicon by Means of X-Ray Extinction Contrast Topography

Published online by Cambridge University Press:  06 March 2019

E. S. Meieran
Affiliation:
Fairchild Semiconductor Palo Alto, California
K. E. Lemons
Affiliation:
Fairchild Semiconductor Palo Alto, California
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Abstract

In order to study the effects of processing variables on the defect contents of silicon wafers, an X-ray extinction contrast camera was designed and constructed to fit on the standard GE XRD-5 table. The camera, in its normal operating position, can be routinely used without interfering with the emission or diffraction instrumentation of the unit, and also can be mounted on the diffractometer stage for diffraction line breadth analysis. Routine laboratory procedures including sample preparation and mounting, film types, and film exposure and development are outlined.

The correlation between extinction contrast topographs and optical photographs of sawed wafers is presented. Wafers were examined in the sawed, lapped, and chemically polished conditions. Subsequent to each processing step in the surface treatment of wafers, a series of topographs was made using four different crystal orientations. In this manner the three-dimensional picture of the defects is obtained, as are the Burger's vectors of all dislocations. It appears that internal defects such as dislocations are more uniformly distributed in lapped and chemically polished wafers than in sawed and chemically polished wafers. Furthermore, different doping impurities and levels cause different amounts of contrast in the dislocation images.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1964

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References

1. Lang, A. R., “The Projection Topograph: A New Method in X-ray Diffraction Microradiography,” Acta. Cryst, 12: 249, 1959.Google Scholar
2. Newkirk, J. B., “The Observation of Dislocations and Other Imperfections by X-ray Extinction Contrast,” Trans. AIME 215: 483, 1959.Google Scholar
3. Jenkinson, A. E. and Lang, A. R., “X-ray Diffraction Topographic Studies of Dislocations in Floating-Zone Grown Silicon,” Conference on Direct Observation of Imperfections in Crystals, Interscience Pubs, Inc., 1962, pp. 471495.Google Scholar
4. James, R. W., The Optical Principles of the Diffraction of X-rays, G. Bell and Sons Ltd., London, 1958, p. 60.Google Scholar
5. Schwuttke, G. H., “X-ray Diffraction Microscopy Study of Imperfections in Silicon Single Crystals,” G.T. & E.R & D Journal 1(2): 68, July 1961.Google Scholar
6. Vogel, F. L. and Lovell, L. C., “Dislocation Etch Fits in Silicon Crystals,’ J. Appl. Phys. 27:14131415, 1956.Google Scholar
7. Dash, W. C., “Copper Precipitation on Dislocations,” J. Appl. Phys. 27:11931195, 1956.Google Scholar