Uniformity evaluation of lattice spacing of silicon crystals for the realization of the kilogram

Abstract

Uniformity of lattice spacing of 28Si enriched single crystals was evaluated by the self-referenced lattice comparator (SRLC). Mapping measurements of the lattice spacing were performed for samples cut from the seed side of two 28Si ingots produced recently by the Physikalisch-Technische Bundesanstalt (PTB) for the realization of the kilogram. Maps of lattice spacing distribution for these new crystals were analyzed and compared to those of the previous crystals. The new crystals had uniform distribution of lattice spacing.

Keywords

• Kilogram realization
• d-spacing of silicon
• Strain measurement
• X-ray diffraction
• Lattice comparison