Anomalous surface transformations in crystalline silicon induced by subpicosecond laser pulses

1986 ◽  
Vol 48 (3) ◽  
pp. 209-211 ◽  
Author(s):  
Yoshihiko Kanemitsu ◽  
Yuzo Ishida ◽  
Ichiroh Nakada ◽  
Hiroto Kuroda
Keyword(s):  
Crystalline Silicon ◽  
Laser Pulses ◽  
Anomalous Surface

Writing waveguides inside monolithic crystalline silicon with nanosecond laser pulses

2016 ◽  
Vol 41 (21) ◽  
pp. 4875 ◽  
Author(s):  
M. Chambonneau ◽  
Q. Li ◽  
M. Chanal ◽  
N. Sanner ◽  
D. Grojo
Keyword(s):  
Crystalline Silicon ◽  
Laser Pulses ◽  
Nanosecond Laser ◽  
Nanosecond Laser Pulses

Surface modifications of crystalline silicon created by high intensity 1064nm picosecond Nd:YAG laser pulses

2007 ◽  
Vol 253 (24) ◽  
pp. 9315-9318 ◽  
Author(s):  
M.S. Trtica ◽  
B.M. Gakovic ◽  
D. Maravic ◽  
D. Batani ◽  
T. Desai ◽  
...  
Keyword(s):  
Nd:Yag Laser ◽  
High Intensity ◽  
Crystalline Silicon ◽  
Surface Modifications ◽  
Laser Pulses

scholarly journals Micro/Nano Amorphization/Oxidation Of Silicon Induced By High Repetition Femtosecond Laser Pulses

2021 ◽  
Author(s):  
Amirkianoosh Kiani
Keyword(s):  
Solar Cell ◽  
Femtosecond Laser ◽  
Surface Temperature ◽  
Pulse Duration ◽  
Analytical Model ◽  
Repetition Rate ◽  
Crystalline Silicon ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Parameters

The main aim of this thesis is to develop a new method for direct micro/nano amorphization/oxidation of silicon using femtosecond laser irradiation and its applications in maskless lithography and solar cell fabrication. Amorphization and oxidation occur when crystalline silicon is exposed to the irradiation of femtosecond laser pulses below the ablation threshold. Mechanisms of morphization and oxidation were discussed and the surface temperature model was developed to study the relation between laser parameters and observed amorphization and oxidation. A systematic theoretical and experimental study of the influence of the laser parameters on the quality of amorphorized area and the size of the feature fabricated through amorphization has been studied. It was found that during the process of silicon amorphization and oxidation, the higher repetition rate of laser pulses yields smooth morphology with better repeatability. Increasing pulse duration and number of pulses were seen to increase the line width. However, increasing the number of pulses does not result in ablation of the target area. An analytical model was developed for the calculation of the average surface temperature after n-pulses. The effect of the laser pulse width was investigated by developing an analytical model for the calculation of the non-dimensional surface temperature with various pulse widths. It was found from experimental and analytical results that for a constant power and repetition rate, an increase in the pulse duration corresponds to a significant increase in the surface temperature. It results in an increase in the amount of modified material as well as improvement of light absorption in the case of amorphization. The main aim of this thesis is to develop a new method for direct micro/nano amorphization/oxidation of silicon using femtosecond laser irradiation and its applications in maskless lithography and solar cell fabrication.Amorphization and oxidation occur when crystalline silicon is exposed to the irradiation of femtosecond laser pulses below the ablation threshold. Mechanisms of morphization and oxidation were discussed and the surface temperature model was developed to study the relation between laser parameters and observed amorphization and oxidation. A systematic theoretical and experimental study of the influence of the laser parameters on the quality of amorphorized area and the size of the feature fabricated through amorphization has been studied. It was found that during the process of silicon amorphization and oxidation, the higher repetition rate of laser pulses yields smooth morphology with better repeatability. Increasing pulse duration and number of pulses were seen to increase the line width. However, increasing the number of pulses does not result in ablation of the target area. An analytical model was developed for the calculation of the average surface temperature after n-pulses.The effect of the laser pulse width was investigated by developing an analytical model for the calculation of the non-dimensional surface temperature with various pulse widths. It was found from experimental and analytical results that for a constant power and repetition rate, an increase in the pulse duration corresponds to a significant increase in the surface temperature. It results in an increase in the amount of modified material as well as improvement of light absorption in the case of amorphization.The amorphous silicon and silicon oxide can act as an etch stop. Therefore, maskless lithography iis possible with the direct patterning (amorphization and oxidation) of crystalline silicon. Experimental results have proved the feasibility of the proposed concepts. The thin-film of amorphous silicon generated on the silicon substrate has a potential for use in photovoltaic devices and solar cell fabrication. In comparison with previous methods, the direct oxidation/amorphization of silicon induced by the femtosecond laser is a maskless single-step technique which offers a higher flexibility and reduced processing time.

scholarly journals Формирование кремниевых наночастиц методом импульсной лазерной абляции пористого кремния в жидкостях

2020 ◽  
Vol 46 (14) ◽  
pp. 13
Author(s):  
А.В. Скобёлкина ◽  
Ф.В. Кашаев ◽  
А.В. Колчин ◽  
Д.В. Шулейко ◽  
Т.П. Каминская ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Porous Silicon ◽  
Crystalline Silicon ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Picosecond Laser Pulses

It was shown that the ablation of meso- and microporous silicon layers by picosecond laser pulses in water and ethanol leads to the formation of nanosilicon suspensions with a diameter of less than 100 nm. It has been demonstrated that the use of porous silicon allows to reduce the thresholds of laser ablation and increase the concentration of particles in suspensions in comparison with the case of crystalline silicon ablation.

Calculation of Carrier and Lattice Temperatures Induced in Si and GaAs By Picosecond Laser Pulses

1981 ◽  
Vol 4 ◽  
Author(s):  
A. Lietoila ◽  
J. F. Gibbons
Keyword(s):  
Crystalline Silicon ◽  
Variable Parameter ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Hot Carriers ◽  
Thermalization Time ◽  
Picosecond Laser Pulses ◽  
Carrier Temperature ◽  
Energy Relaxation Time ◽  
532 Nm

ABSTRACTA previously presented computer model was used to calculate melt thresholds and carrier temperatures in crystalline silicon and gallium arsenide subjected to picosecond laser pulses at 532 nm. The energy relaxation time of hot carriers was a variable parameter. For Si, a thermalization time of 1 ps yields results which are in very satisfactory agreement with published experimental data: the melt threshold is 0.19 J/cm2, and the maximum carrier temperature for the threshold pulse is 5500 K. The melt threshold in GaAs is substantially less, 0.03 J/cm2 for a thermalization time of 1 ps.

Heterogeneous Nucleation of Spatially Coherent Damage Structures in Crystalline Silicon with Picosedcond 1.06 μm and 0.53 μm Laser Pulses

1980 ◽  
Vol 1 ◽  
Author(s):  
R.M. Walser ◽  
M.F. Becker ◽  
J.G. Ambrose ◽  
D.Y. Sheng
Keyword(s):  
Electric Field ◽  
Heterogeneous Nucleation ◽  
Crystallographic Orientation ◽  
Free Space ◽  
Crystalline Silicon ◽  
Laser Pulses ◽  
Laser Wavelength ◽  
Beam Spot ◽  
Polarized Beams ◽  
Linearly Polarized

Several types of periodic ripple structures have been observed on the surface of solids that have been laser irradiated with beam intensities near their melting thresholds.1-7 We restrict our attention here to the coherent, onedimensional (RD) gratings induced by linearly polarized beams.3-7 These gratings have a period close to the free space laser wavelength (λ0) for normally incident beams and are normally found in the beam spot near the melt boundary (Fig. 1). The grating lines are always perpendicular to the optical electric field Ei independent of the crystallographic orientation of the sample.

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