Silicon Thin Film
Novosibirsk State University, A.V. Rzhanov Institute of Semiconductor Physics SB RAS
Lavrentiev Ave. 13, 630090, Novosibirsk, Russia
Scientific specialization: Physics of semiconductors, optics of semiconductor nanostructures.
Field of interest: Semiconductors, semiconductor nanostructures, defects, Raman scattering, luminescence, phonons, phonon-plasmon interaction, laser treatments of nanostructures, LEDs, solar cells, dielectrics, memristors.
1984-1986 Student of Novosibirsk State University (NSU), Physics Department.
1986-1988 Private (soldier) in Soviet Army.
1988-1991 Student of NSU, Physics Department, specialized on Chair of Physics of Semiconductors.
1991-1993 Researcher-engineer in Institute of Semiconductor Physics (ISP) of Siberian Branch of Russian Academy of Sciences (SB RAS)
1993-1997 Junior-researcher in ISP SB RAS
1997-2001 Researcher, group leader in ISP SB RAS
2001-present time Senior researcher, group leader in ISP SB RAS
EDUCATIONAL WORK, TEACHING
1997-present time Assistant professor in NSU (course of Electrodynamics, Chair of General physics).
1999-2000 Assistant professor in NSU (course of Physics of Condenced Matter, Chair of Physics of semiconductors).
2003-2005 Assistant professor in NSU (course of Semiconductor Physics, Chair of Physics of Semiconductors).
2006-2018 Associated professor in NSU (lecture course of Physical bases of Microelectronics, Chair of Automation of Physical-Technical Studies).
2018-present time Professor in NSU (lecture course of Physical bases of Microelectronics, Chair of Automation of Physical-Technical Studies, course of Electrodynamics, Chair of General physics).
Supervisor of PhD students –
T.T. Korchagina, PhD thesis “Formation of silicon nanocrystals in dielectric films by pulsed laser annealings”, defended in 2012.
D.V. Marin, PhD thesis “The optical properties of germanium nanocrystals in germanium oxide films”, defended in 2014.
S.G. Cherkova, PhD thesis “Formation and modification of silicon light-emission nanostructures using radiation methods”, defended in 2018.
K.N. Astankova, PhD thesis “Fabrication of metastable GeO films and their modification with atomic force microscope probe and laser irradiation”, defended in 2021.
Abstract for Presentation
Femto- and picosecond infrared laser crystallization of amorphous Si:H films with included amorphous Ge layers
Pulsed laser annealing is efficiently used for crystallization and nano-structuring of amorphous semiconductor films. In the case of narrow-band semiconductor (for example Ge) layers included in a-Si, a pulsed infrared laser annealing (PIRLA) technique allows to selectively crystallize regions that absorb IR light. Such structures can be used in p-i-n photodiodes or solar cells.
In the present study, a-Si:H/a-Ge:H multilayer structures (MLS) consisted of 4 silicon (40 nm) and 3 germanium (15 nm) alternating amorphous layers were produced by plasma enhanced chemical vapor deposition on glass and Si(100) substrates. The MLS samples were annealed by a picosecond laser (HiLASE PERLA-B, λ=1030 nm, pulse duration 1.4 ps) and a femtosecond laser in combination with optical parametric amplifier (Coherent Astrella/TOPAS, λ=1500 nm, 70 fs) in a wide range of the pulse energy density (laser fluence) from 20 to 200 mJ/cm2 under single-shot and multishot irradiation conditions. The structural analysis was performed by Raman spectroscopy using a T64000 spectrometer with micro-Raman setup and an Ar laser (514.5 nm) as an excitation source. The Raman spectrum of the as-deposited MLSs contains broad bands at ~480 cm–1 and ~275 cm–1 related to maximum density of vibrational states of a-Si and a-Ge, respectively. The vibration frequencies of Ge–Si bonds, which are present at the Ge/Si heteroboundaries, are ~400 cm–1 but the spectrum of as-deposited MLS reveals almost no features at this frequency indicating that the concentration of these bonds is low.
Several regimes of PIRLA with increasing laser fluence are found for both ps and fs pulses. (1) At low fluences, the Ge layers are crystallized while the Si layers remain amorphous without noticeable intermixing of Ge and Si. (2) The Ge layers are almost fully crystallized without observable Si crystallization but some Ge-Si intermixing occurs. (3) Complete crystallization of the Ge layers with partial crystallization of Si layers and Ge-Si intermixing. (4) Almost complete intermixing of the Ge and Si layers in the MLS. (5) Partial ablation of the MLS.
A theoretical analysis of ps and fs PIRLA of the MLS, taking into account one- and two-photon excitation, shows that, in a wide range of laser fluence, germanium can be laser-heated to the melting point while heating of silicon is negligible.
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23-26 August, Nanjing, China
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