Quantification of the Void Volume in Single-Crystal Silicon

D'Agostino, G.; Luzio, Marco Di; Mana, Giovanni; Martino, Luca; Oddone, Massimo; Sasso, C.P.

doi:10.1021/acs.analchem.6b03260

Cited by 5 publications

(4 citation statements)

References 19 publications

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“…The measurement of an upper limit to the number concentration of vacancies, C vac , trapped into voids is planned by using a method based on Cu decoration and neutron activation. The method was formerly applied to a 5 cm long and 1 cm thick rectangular parallelepiped sample of natural silicon and a 1 × 10 14 cm −3 upper limit of C vac was established [14].…”

Section: Point Defectsmentioning

confidence: 99%

A new²⁸Si single crystal: counting the atoms for the new kilogram definition

et al. 2017

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A new single crystal from isotopically enriched silicon was used to determine the Avogadro constant N A by the x-ray-crystal density method. The new crystal, named Si28-23Pr11, has a higher enrichment than the former 'AVO28' crystal allowing a smaller uncertainty of the molar mass determination. Again, two 1 kg spheres were manufactured from this crystal. The crystal and the spheres were measured with improved and new methods. One sphere, Si28kg01a, was measured at NMIJ and PTB with very consistent results. The other sphere, Si28kg01b, was measured only at PTB and yielded nearly the same Avogadro constant value. The mean result for both 1 kg spheres is N A = 6.022 140 526(70) × 10 23 mol −1 with a relative standard uncertainty of 1.2 × 10 −8 . This value deviates from the Avogadro value published in 2015 for the AVO28 crystal by about 3.9(2.1) × 10 −8 . Possible reasons for this difference are discussed and additional measurements are proposed.

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Section: Point Defectsmentioning

confidence: 99%

A new²⁸Si single crystal: counting the atoms for the new kilogram definition

et al. 2017

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“…They estimated that hexavacancy V 6 is a candidate for explaining their PALS results. D'Agostino et al [4] developed a method to measure the void concentration of 10 14 cm −3 in a silicon crystal with a few percent uncertainties using Cu decoration and neutron activation.…”

Section: Introductionmentioning

confidence: 99%

Electron Paramagnetic Resonance Study on ²⁸Si Single Crystal for the Future Realization of the Kilogram

Mizushima

Kuramoto

Fujii

et al. 2019

IEEE Trans. Instrum. Meas.

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For the future realization of the kilogram using the X-ray crystal density (XRCD) method, isotopically enriched silicon crystals grown by the floating zone method are employed. In this paper, we present quantitative electron paramagnetic resonance (EPR) measurements on 28 Si single crystal AVO28 to increase the reliability of mass deficit correction in the XRCD method. We detected phosphorus impurity in the crystal and determined its concentration to be 3.2(5) × 10 12 cm −3 , which is consistent with that estimated using Fourier transform infrared spectroscopy. In addition, the EPR measurements revealed that the concentrations of nine types of vacancy defects with unpaired electrons in the crystal are less than 1 × 10 12 cm −3 at 25 K both in a dark environment and under illumination. As a result, the necessary mass deficit correction due to these vacancy defects is estimated to be 0.0(2) µg for 1-kg AVO28 spheres.

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“…With respect to point defects, previous Avogadro silicon materials were measured using positron lifetime and copper decoration to determine vacancies. , In addition, infrared spectroscopy was used to quantify carbon, oxygen, boron, nitrogen, and INAA to probe a large number of the remaining elements. − …”

Section: Instrumental Neutron Activation Analysismentioning

confidence: 99%

“…With respect to point defects, previous Avogadro silicon materials were measured using positron lifetime and copper decoration to determine vacancies. 5,6 In addition, infrared spectroscopy was used to quantify carbon, oxygen, boron and nitrogen, 5 and INAA to probe a large number of the remaining elements. 7,8,9 With the aim of collecting experimental data on the contamination of the new material, a sample of one of the 28 Si-enriched single crystal ingots was allocated to be investigated by INAA.…”

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confidence: 99%

Impurities in a ²⁸Si-Enriched Single Crystal Produced for the Realization of the Redefined Kilogram

et al. 2017

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The practical realization of the unit of mass is possible by manufacturing a perfect one-kilogram sphere from a Si-enriched single crystal. The mass of the sphere can be determined in terms of a fixed value of the Planck constant by counting the number of silicon atoms in the core of the single crystal. To reach the target 2.0 × 10 relative standard uncertainty, the mass of the surface layer and the mass deficit due to point defects such as impurities and vacancies must be investigated and corrected for. A sample of a Si-enriched single crystal produced to test the possibility of obtaining material at a scale useful to the dissemination of mass standards was measured by instrumental neutron activation analysis to check the purity with respect to a large number of possible contaminant elements. The results collected in a neutron activation experiment performed with the high thermal neutron flux available at the 20 MW OPAL research reactor are described. The data collected in this study showed that the produced material has a purity level never achieved with silicon used to manufacture previous one-kilogram spheres.

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Quantification of the Void Volume in Single-Crystal Silicon

Cited by 5 publications

References 19 publications

A new²⁸Si single crystal: counting the atoms for the new kilogram definition

A new²⁸Si single crystal: counting the atoms for the new kilogram definition

Electron Paramagnetic Resonance Study on ²⁸Si Single Crystal for the Future Realization of the Kilogram

Impurities in a ²⁸Si-Enriched Single Crystal Produced for the Realization of the Redefined Kilogram

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Quantification of the Void Volume in Single-Crystal Silicon

Cited by 5 publications

References 19 publications

A new28Si single crystal: counting the atoms for the new kilogram definition

A new28Si single crystal: counting the atoms for the new kilogram definition

Electron Paramagnetic Resonance Study on 28Si Single Crystal for the Future Realization of the Kilogram

Impurities in a 28Si-Enriched Single Crystal Produced for the Realization of the Redefined Kilogram

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A new²⁸Si single crystal: counting the atoms for the new kilogram definition

A new²⁸Si single crystal: counting the atoms for the new kilogram definition

Electron Paramagnetic Resonance Study on ²⁸Si Single Crystal for the Future Realization of the Kilogram

Impurities in a ²⁸Si-Enriched Single Crystal Produced for the Realization of the Redefined Kilogram