Certifying the Degree of Perfection of Silicon Single Crystals for the Avogadro Project by Measuring the Amount of Copper Silicide Precipitated in the Voids

Author

Spaepen, F. ; Wen, C.Y. ; Quétel, C. ; Aninkevicius, V. ; Filee, K. ; Proost, J. ; Taylor, P.D.P. ; De Bievre, P.

Author_Institution

Div. of Eng. & Appl. Sci., Harvard Univ., Cambridge, MA

fYear

2004

fDate

38139

Firstpage

147

Lastpage

148

Abstract

A procedure has been developed for determining the number of missing atoms in a silicon crystal. Possible voids are filled with Cu ⁵Si by indiffusion of copper. After removal of the interstitially dissolved copper, the samples are digested and the copper content is determined by isotope-dilution mass spectrometry. The detection limit of this highly specific and accurate measurement method was developed sufficiently to certify the degree perfection of the silicon single crystals used to enable a redetermination of the Avogadro constant, N_A, to the required level: lower than 2 times 10 ^-8 N_A combined standard uncertainty

Keywords

constants; copper; copper compounds; mass spectroscopy; silicon; voids (solid); Avogadro constant; Avogadro project; Cu⁵Si; Si; copper indiffusion; copper silicide; isotope-dilution mass spectrometry; silicon single crystals; Atomic measurements; Copper; Crystalline materials; Crystallization; Crystals; Lattices; Mass spectroscopy; Silicides; Silicon; Uncertainty;

fLanguage

English

Publisher

ieee

Conference_Titel

Precision Electromagnetic Measurements Digest, 2004 Conference on

Conference_Location

London

Print_ISBN

0-7803-8494-6

Electronic_ISBN

0-7803-8494-6

Type

conf

DOI

10.1109/CPEM.2004.305503

Filename

4097158