Enhanced dopant solubility in strained silicon

• Published in: Physica status solidi. C Vol. 2; no. 6; pp. 1953 - 1957
• Main Authors: Adey, J., Jones, R., Briddon, P. R.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.04.2005; WILEY‐VCH Verlag
• Subjects: 61.72.Ji; 61.72.Tt; 71.15.Nc
• ISSN: 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200460535

The equilibrium solubility of substitutional boron and arsenic has been evaluated for silicon under various compressive and tensile biaxial strains using local density functional theory. The solubility of boron is increased by compressive strain for two reasons. The smaller size of the boron atom leads to a solubility enhancement with compressive strain but more significantly the solubility of the ionised acceptor is greatly enhanced due to the strain induced raising of the Fermi‐level. The larger dopant, arsenic, is actually found to result in an almost null change in lattice constant in agreement with x‐ray scattering experiments. For arsenic, an increased solubility with tensile strain comes entirely from the lowering of the Fermi‐level. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)