Structural Anisotropy of Amorphous Silicon Films Modified by Femtosecond Laser Pulses

Journal Article · Fri Jun 15 04:00:00 EDT 2018 · Optics and Spectroscopy

DOI:https://doi.org/10.1134/S0030400X18060218· OSTI ID:22786408

Kashaev, F. V.; Potemkin, F. V.; Zabotnov, S. V.; Zoteev, A. V.; Presnov, D. E. ^[1]; Parkhomenko, I. N.; Romanov, I. A. ^[2]

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1. Moscow State University, Faculty of Physics (Russian Federation)
2. Belarus State University (Belarus)

It is demonstrated that the surface-relief orientation in the form of one-dimensional gratings with a period of 1.20 ± 0.02 μm formed under processing of hydrogenated-silicon films by femtosecond laser pulses (1.25 μm) with an energy density of 0.15 J/cm{sup 2} is determined by the direction of the polarization vector of the radiation and total laser exposure. Based on the results of the analysis of Raman spectra, the presence of a nanocrystalline phase of silicon with a volume fraction between 15 and 67% (depending on processing conditions) is detected. The observed processes of micro- and nanostructuring are caused by excitation of the surface plasmon–polaritons and nanocrystallization in the near-surface region in the field of high-power femtosecond laser pulses, respectively. In addition, formation of polymorph modifications of silicon Si-III and Si-XII under femtosecond laser processing with a number of pulses exceeding 500 is discovered. Anisotropy of the Raman signal for the above polymorph modifications is revealed.

• OSTI ID: 22786408
• Journal Information: Optics and Spectroscopy, Journal Name: Optics and Spectroscopy Journal Issue: 6 Vol. 124; ISSN 0030-400X; ISSN OPSUA3
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
CRYSTALS
ENERGY DENSITY
EXCITATION
FILMS
HYDROGENATION
LASER RADIATION
MODIFICATIONS
NANOSTRUCTURES
POLARIZATION
PULSES
RAMAN SPECTRA
SILICON
SURFACES