Ablation of Si and Ge Using UV Femtosecond Laser Pulses

1995 ◽  
Vol 397 ◽  
Author(s):  
G. Herbst ◽  
M. Steiner ◽  
G. Marowsky ◽  
E. Matthias
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Material Removal ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Bond Breaking ◽  
Intensity Enhancement ◽  
Silicon And Germanium

ABSTRACTLaser ablation of silicon and germanium was carried out in moderate vacuum with l00fs to 400fs pulses at 248nm and intensities up to 3x1013 W/cm2. Evidence for non-thermal material removal was found. Imaged multishot ablation patterns display the intensity dependent self-structuring effect, forming well-known columnar structures. It is shown that continued irradiation of these structures eventually results in comparatively clean ablation. An increase of ablation rate with depth was observed. The reason is an intensity enhancement inside the pits by reflective focussing to a level where bond-breaking takes place. Furthermore, it was noticed that ablation contours can be significantly improved by electrically grounding the target.

scholarly journals Femtosecond laser ablation of brass: A study of surface morphology and ablation rate

2012 ◽  
Vol 30 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Brian J. Fryer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Surface Morphology ◽  
Fine Particles ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Ambient Air ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Nanosecond Laser

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.

scholarly journals Laser ablation of silicon with THz bursts of femtosecond pulses: an experimental and theoretical investigation

2021 ◽  
Author(s):  
Caterina Gaudiuso ◽  
Pavel N. Terekhin ◽  
Annalisa Volpe ◽  
Stefan Nolte ◽  
Bärbel Rethfeld ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Thermal Load ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Pulse Mode ◽  
Femtosecond Laser Pulses ◽  
Photon Absorption ◽  
Burst Frequency ◽  
Two Photon Absorption ◽  
Theoretical Investigations

Abstract In this work, we performed an experimental investigation supported by a theoretical analysis, to improve knowledge on the laser ablation of silicon with THz bursts of femtosecond laser pulses. Laser ablated craters have been created using 200 fs pulses at a wavelength of 1030 nm on silicon samples systematically varying the burst features and comparing to the Normal Pulse Mode (NPM). Using bursts in general allowed reducing the thermal load to the material, however, at the expense of the ablation rate. The higher the number of pulses in the bursts and the lower the intra-burst frequency, the lower is the specific ablation rate. However, bursts at 2 THz led to a higher specific ablation rate compared to NPM, in a narrow window of parameters. Theoretical investigations based on the numerical solution of the density-dependent two temperature model revealed that lower lattice temperatures are reached with more pulses and lower intra-burst frequencies, thus supporting the experimental evidence of the lower thermal load in Burst Mode (BM). This is ascribed to the weaker transient drop of reflectivity, which suggests that with bursts less energy is transferred from the laser to the material. This also explains the trends of the specific ablation rates. Moreover, we found that two-photon absorption plays a fundamental role during BM processing in the THz frequency range.

Femtosecond Laser Ablation of Zr55Al10Ni5Cu30 Bulk Metallic Glass

2007 ◽  
Vol 539-543 ◽  
pp. 1951-1954 ◽  
Author(s):  
Tomokazu Sano ◽  
Kengo Takahashi ◽  
Akio Hirose ◽  
Kojiro F. Kobayashi
Keyword(s):  
Laser Ablation ◽  
Metallic Glass ◽  
Femtosecond Laser ◽  
Bulk Metallic Glass ◽  
Pulse Energy ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ablation Depth ◽  
Polished Surface

Dependence of the femtosecond laser ablation depth on the laser pulse energy was investigated for Zr55Al10Ni5Cu30 bulk metallic glass. Investigation of the femtosecond laser ablation of bulk metallic glasses has not been reported. Femtosecond laser pulses (wavelength of 800 nm, pulse width of 100 fs, pulse energies of 2 – 900 μJ) were focused and irradiated on the polished surface of metals in air. The ablation depth of the metallic glass is deeper than that of its crystallized metal at a pulse energy in the strong ablation region. We suggest that the energy loss at grain boundaries of hot electrons which is accelerated by the laser electric field influence the ablation depth in the strong ablation region.

scholarly journals Фемтосекундный лазерный отжиг многослойных тонкопленочных структур на основе аморфных германия и кремния

2020 ◽  
Vol 46 (11) ◽  
pp. 43
Author(s):  
А.В. Колчин ◽  
Д.В. Шулейко ◽  
А.В. Павликов ◽  
С.В. Заботнов ◽  
Л.А. Головань ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Amorphous Silicon ◽  
Laser Annealing ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Surface Structures ◽  
Multilayered Structures ◽  
Spectra Analysis ◽  
Periodic Surface ◽  
Silicon And Germanium

Femtosecond laser annealing of thin-film multilayered structures based on amorphous silicon and germanium were studied. The original samples were synthesized via plasma-enhanced deposition on glass substrate. Scanning electron microscopy revealed formation of periodic surface structures in the irradiated films. Raman spectra analysis revealed crystallization of amorphous germanium as a result of femtosecond laser pulses action, as well as fluence-dependent mixture of the germanium and silicon layers at absence of crystallization of the amorphous silicon layers.

Nanoparticle Aluminum Preparation

2019 ◽  
Author(s):  
Soma Venugopal Rao ◽  
Krishnamurthi Muralidharan ◽  
Anuj A. Vargeese
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Energetic Materials ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Aluminum Nanoparticles ◽  
Chemical Methods ◽  
Laser Ablation In Liquids ◽  
Recent Developments ◽  
Green Technique

An overview of recent developments in the synthesis of aluminum nanoparticles (Al NPs) and their applications in the field of energetic materials is presented. Various methods of preparing the Al NPs of different sizes including physical (laser ablation) and chemical methods are highlighted. Some of the results obtained by our group on the passivation of the Al NPs are highlighted. The laser ablation in liquids technique with ultrashort (picosecond and femtosecond) laser pulses is a green technique for preparing Al NPs devoid of any precursors, whereas the chemicals method yields passivated Al NPs. Among the various applications of the Al NPs, energetic applications are discussed in detail. This article is concluded by emphasizing the prospects of Al NPs in various energetic applications and the future of different techniques to synthesize them.

scholarly journals Formation of Periodic Nanoripples on Silicon and Germanium Induced by Femtosecond Laser Pulses

2011 ◽  
Vol 12 ◽  
pp. 29-36 ◽  
Author(s):  
R. Le Harzic ◽  
D. Dörr ◽  
D. Sauer ◽  
M. Neumeier ◽  
M. Epple ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Silicon And Germanium

scholarly journals Laser ablation of titanium in the medium of n-hexane by femtosecond laser pulses at various pressures

2019 ◽  
Vol 1331 ◽  
pp. 012012
Author(s):  
A S Chernikov ◽  
D A Kochuev ◽  
A V Ivashchenko ◽  
K S Khorkov ◽  
A A Voznesenskaya ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses
Sign in / Sign up

Export Citation Format

Share Document