Title :
Density comparison measurements of silicon crystals by pressure of flotation method
Author :
Waseda, A. ; Fujii, K.
Author_Institution :
Nat. Inst. of Adv. Ind. Sci. & Technol., Nat. Metrol. Inst. of Japan, Tsukuba, Japan
Abstract :
Since silicon single crystals are believed to be the most perfect crystals to be obtained at the present time, they are used for the density standard and the determination of the Avogadro constant. However, there exists molar volume discrepancies among them. It is thought that the problems exist in the degree of perfection of the silicon crystal. It is important, therefore, to study defect and impurity effects on the density of silicon in order to clarify the cause of the discrepancies. We have developed a density comparison measurement system based on the pressure of flotation method (PFM). Density differences for silicon spheres produced from a new FZ-silicon ingot of NRLM4 was measured. The second generation of this PFM apparatus is being installed in the National Metrology Institute of Japan (NMIJ).
Keywords :
constants; crystal defects; density measurement; impurities; measurement standards; measurement uncertainty; silicon; Avogadro constant determination; NRLM4 FZ-silicon ingot; PFM; Si; Si crystal density comparison measurements; density comparison measurement system; density standard; measurement uncertainty; pressure of flotation measurement method; silicon crystal degree of perfection; silicon density defect/impurity effects; silicon single crystal molar volume discrepancies; silicon sphere density differences; Crystals; Density measurement; Impurities; Isothermal processes; Lattices; Metrology; Pressure control; Pressure measurement; Silicon; Temperature distribution;
Conference_Titel :
Precision Electromagnetic Measurements, 2002. Conference Digest 2002 Conference on
Conference_Location :
Ottawa, Ontario, Canada
Print_ISBN :
0-7803-7242-5
DOI :
10.1109/CPEM.2002.1034840
