Density functional theory calculations of the stress of oxidised (1 1 0) silicon surfaces. (4th November 2016)

• Record Type: Journal Article
• Authors: Melis, C; Giordano, S; Colombo, L; Mana, G
• Is Part Of: Metrologia. Volume 53:Number 6(2016:Dec.)
• Page Start: 1339
• Page End: 1345
• Publication Date: 2016-11-04
• Subjects: units and standards -- determination of fundamental constants -- structure of clean and oxidised surfaces -- surface stress -- mechanical properties; Weights and measures -- Periodicals; Weights and Measures -- Periodicals; 530.805
• DOI: 10.1088/0026-1394/53/6/1339
• Languages: English
• ISSNs: 0026-1394

Abstract

Abstract: The measurement of the lattice-parameter of silicon by x-ray interferometry assumes the use of strain-free crystals. This might not be the case because surface relaxation, reconstruction, and oxidation cause strains without the application of any external force. In a previous work, this intrinsic strain was estimated by a finite element analysis, where the surface stress was modeled by an elastic membrane having a 1 N m −1 tensile strength. The present paper quantifies the surface stress by a density functional theory calculation. We found a value exceeding the nominal value used, which potentially affects the measurement accuracy.