Structural damage and ion‐channelling effects in a single‐crystal Si layer modified by medium‐heavy ions. (13th July 2018)

• Record Type: Journal Article
• Authors: Mikšová, R.; Macková, A.; Jagerová, A.; Yatskiv, R.
• Is Part Of: Surface and interface analysis. Volume 50:Number 11(2018)
• Page Start: 1243
• Page End: 1249
• Publication Date: 2018-07-13
• Subjects: ion irradiation of crystals -- MC modelling of ion channelling -- RBS channelling -- SOI material; Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Thin films -- Periodicals; 541.33
• DOI: 10.1002/sia.6492
• Languages: English
• ISSNs: 0142-2421

Abstract

Abstract : Structural modification after medium‐heavy ion irradiation was characterised by Rutherford backscattering spectrometry in the channelling mode (RBS‐C) for silicon‐on‐insulator (SOI) material. Silicon on insulator was irradiated using C +, 2+, N +, 2+, and O +, 2+ ions at fluences of 1 × 10 14 and 1 × 10 15 cm −2 and energies of 0.4, 3, and 5 MeV to follow the interplay of electronic and nuclear stopping and its influence on damage accumulation. The relative amount of displaced atoms in the surface‐irradiated layer was extracted from RBS‐C spectra and used, along with axial channel analysis, to study ion‐channelling effects in the modified crystalline lattice. The discussion of ion penetration through the modified crystalline layer of the SOI structure in channelling direction was supported by a Monte Carlo simulation (FLUX code) of He ion flux maps in a gradually modified Si crystalline upper layer taking into account the experimentally determined relative disorder extracted from RBS‐C. The RBS‐C measurement shows an increase of the relative amount of displaced atoms mainly after irradiation using 0.4‐MeV ions at an ion fluence of 1 × 10 15 cm −2 . The narrowing effect of channels for He ion‐beam channelling experiment was observed in the irradiated silicon layers and discussed in connection with the irradiation parameters. The FLUX simulation, provided with the experimentally given value of the displaced atoms, has confirmed that it is not only the vacancies that can cause such a narrowing effect of the angular scan. The angular scan narrowing can be explained for predominately electronic stopping by induced crystalline‐cell modification.