Femtosecond laser interaction with pulsed-laser deposited carbon thin films of nanoscale thickness
Year: 2010
Type: article
Abstract: The dependence of optical, electronic and thermal penetration zones on the thickness of nanoscale layers grown on silicon wafers is reported. Tetrahedral amorphous carbon (ta-C) and amorphous carbon nitride (a-C x N y ) films were prepared by inverse pulsed laser deposition (IPLD). Single-pulse modification thresholds for femtosecond laser processing proved to be dependent on the actual film thickness below 60 nm for ta-C and 90 nm for a-C x N y . The modification behaviour was governed by multiphoton processes. An effective penetration depth of the laser radiation in a-C x N y was of ca. 110 nm in accordance with two-photon absorption. Both the emergence length of ballistic hot electrons and the heat diffusion length are negligible in these thin film materials. The lower bulk value of the threshold fluence of the a-C x N y films as compared to ta-C is mainly controlled by optical contributions due to nitrogen-related defects.
Source: Applied Physics A
Authors: M. Forster, L. Égerházi, C. Haselberger, C. Huber, W. Kautek
Institutions: University of Vienna, University of Szeged
Language: English
Subfield: Industrial and Manufacturing Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
OpenAlex ID: W2006034870