Nanostructures on SiC Surface Created by Laser Microablation
Applied Surface Science 2008
L. Fedorenko, Artūrs Medvids, M. Yusupov, V. Yukhimchuck, S. Krylyuk, A. Evtukh

Silicon carbide (SiC), as it is well-known, is inaccessible to usual methods of technological processing. Consequently, it is important to search for alternative technologies of processing SiC, including laser processing, and to study the accompanying physical processes. The work deals with the investigation of pulsed laser radiation influence on the surface of 6H–SiC crystal. The calculated temperature profile of SiC under laser irradiation is shown. Structural changes in surface and near-surface layers of SiC were studied by atomic force microscopy images, photoluminescence, Raman spectra and field emission current–voltage characteristics of initial and irradiated surfaces. It is shown that the cone-shaped nanostructures with typical dimension of 100–200 nm height and 5–10 nm width at the edge are formed on SiC surface under nitrogen laser exposure. The average values of threshold energy density at which formation of nanostructures starts on the 0 0 0 1 and 0 0 0 1surfaces of n-type 6H–SiC(N), nitrogen concentration are determined to be 3.5 J/cm2 and 3.0 J/cm2, respectively. The field emission appeared only after laser irradiation of the surface at threshold voltage of 1000 Vat currents from 0.7 mA to 0.7 mA. The main role of the thermogradient effect in the processes of mass transfer in prior to ablation stages of nanostructure formation under UV laser irradiation (LI) was determined.We ascertained that the residual tensile stresses appear on SiC surface as a result of laser microablation. The nanostructures obtained could be applied in the field of sensor and emitting extreme electronic devices.


Keywords
Silicon carbide; Laser ablation; Nanostructures; Field emission; Photoluminescence; Raman spectra
DOI
10.1016/j.apsusc.2007.08.048
Hyperlink
http://www.sciencedirect.com/science/article/pii/S016943320701207X

Fedorenko, L., Medvids, A., Yusupov, M., Yukhimchuck, V., Krylyuk, S., Evtukh, A. Nanostructures on SiC Surface Created by Laser Microablation. Applied Surface Science, 2008, Vol.254, Iss.7, pp.2031-2036. ISSN 0169-4332. Available from: doi:10.1016/j.apsusc.2007.08.048

Publication language
English (en)
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